Original Russian Text © 2020 N.V. Lukina, A.P. Geraskina, A.V. Gornov et al. published in Forest Science Issues Vol. 3, No. 4, pp. 1-90

N.V. Lukina^1*, A.P. Geraskina¹, A.V. Gornov¹, N.E. Shevchenko¹, A.V. Kuprin², T.I. Chernov³, S.I. Chumachenko^1,4, V.N. Shanin^1,5,6, A.I. Kuznetsova¹, D.N. Tebenkova¹, M.V. Gornova¹

¹Center for Forest Ecology and Productivity of the Russian Academy of Sciences

84/32 Profsoyuznaya St., bldg 14, Moscow, 117997, Russian Federation

²Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far Eastern Branch of the Russian Academy of Sciences

159 Stoletiya prospekt, Vladivostok, 690022, Russian Federation

³Dokuchaev Soil Science Institute

7/2 Pyzhyovskiy lane, Moscow, 397463, Russian Federation

⁴Mytischi Branch of Bauman Moscow State Technical University

11 Institutskaya St., Mytischi, Moscow region, 141005, Russian Federation

⁵Institute of Physicochemical and Biological Problems in Soil Sciences of the Russian Academy of Sciences 2 Institutskaya St., Puschino, 142290, Russian Federation

⁶Institute of Mathematical Problems of Biology RAS – the Branch of Keldysh Institute of Applied Mathematics of the Russian Academy of Sciences

1 Prof. Vitkevich St. Puschino, 142290, Russian Federation

^*Email: nvl07@yandex.ru

Received 30.11.2020

Accepted 22.12.2020

    The problem of assessing the impact of biodiversity on the climate-regulating functions of forests is fundamental. It is of great applied importance for sustainable forest management in the context of global climate change. On the one hand, climate change affects biodiversity; on the other hand, biodiversity underlies the mechanisms of adaptation of forests and society to these changes, because it is a provider of all ecosystem functions. This article aims to discuss scientific issues currently faced by scientists, such as the relationships between biodiversity and climate-regulating functions of forests, and to outline the perspective of the studies. There are numerous studies that describe the influence of certain plant and animal species – ecosystem engineers – on the ecosystem, including climate-regulating functions of forests. However, we lack estimates of the combined effect of the diversity of biota of different trophic levels and groups on the completeness of the implementation of climate-regulating functions of forests of different types/at different succession stages. We emphasise the importance of accounting for such estimates as taxonomic, including genetic, and the functional and structural diversity of forests. We considered various concepts of forest management, taking into account the conservation and restoration of biodiversity. The most important aspect of this problem is estimates and forecasts of interrelationships (trade-offs and synergies) between climate-regulating and other ecosystem functions of forests characterised by different levels of biodiversity, with their natural development and with the combined impact of various natural and anthropogenic factors on forests, including climate change, fires, and forest management regimes. Integration of mathematical models is a promising approach to assess and predict the dynamics of relationships between various ecosystem functions of forests.

Key words: forest ecosystems, taxonomic biodiversity, functional biodiversity, structural biodiversity, ecosystem functions, adaptation to climate change

INTRODUCTION

Forests fulfill many ecosystem functions and provide numerous ecosystem services to humans. Biodiversity provides ecosystem functions and forest services (TEEB, 2010). Globally, nearly half of all species are predicted to become extinct over the next 100 years due to changing land use, anthropogenic influences on biogeochemical cycles, the spread of invasive species, unbalanced management, and uncontrolled exploitation of natural resources (Louman et al., 2011; Rampino, Shen, 2019). A decline in biodiversity will inevitably lead to disruptions in ecosystems.

In the past 25 years, we have witnessed the development of a new scientific direction, aimed at exploring the links between biodiversity and ecosystem functions (BEF) (Eisenhauer et al., 2019; Van der Plas, 2019). Previously, a large proportion of scientific research was aimed at assessing the impact of abiotic factors (geological, climatic) on ecosystems, although the importance of species diversity for the functioning of ecosystems was shown by Ch. Darwin and A.R. Wallace more than 150 years ago (see Eisenhauer et al., 2019). A meta-analysis of the results of short-term experiments on small, artificially created sites (up to 100 m²) demonstrates the existence of stable relationships between biodiversity changes in experiments and ecosystem functioning (Cardinale et al., 2011; O’Connor et al., 2017). The latest studies have focused on natural ecosystems. Analysis of the results of 259 case studies on over 700 cases of relationships between biodiversity and ecosystem functioning demonstrates that biodiversity contributes to biomass production and stabilisation of this process over time, as well as successful pollination (Van der Plas, 2019). The number of cases that showed a positive effect of biodiversity on the rate of organic matter decomposition and multifunctionality of ecosystems exceeded the number of cases with a negative effect, but neutral relationships were quite common. It has been emphasised that assessments of links between biodiversity and ecosystem functions focus on taxonomic diversity, although functional diversity is a more informative predictor. It remains unclear how the links between biodiversity and functions change at different spatial levels, although more positive relationships are expected at higher spatial levels (Van der Plas, 2019). The analysis also showed that the relationships between biodiversity and ecosystem functioning are context sensitive, that is, they change depending on natural and climatic conditions, management regimes, and disturbances (Eisenhauer et al., 2019).

Climate change is one of global challenges, and mitigation and adaptation to climate change are of particular importance today (IPCC, 2019). The global loss of biodiversity is associated with forest degradation. This process can negatively affect forest functioning and resilience in a changing climate. The problem of assessing the impact of biodiversity on the climate-regulating functions of different types of forests is fundamental and of great applied importance for sustainable forest management in the context of global changes. On the one hand, climate change affects biodiversity; on the other hand, biodiversity underlies the mechanisms of adaptation of forests and society to climate change. However, many forest countries, including Russia, have shown a steady trend towards the intensification of forest use, with a consequent decrease in biodiversity (Karpachevsky et al., 2015). In developed countries, this trend is associated with the development of a bioeconomy. It is driven by the increasing demand for forest products and services by the growing population of Earth and per capita consumption (Pülzl et al., 2014).

The assessment of the climate-regulating functions of forests, which include the production of biomass, the regulation of carbon and nitrogen cycles, including the decomposition and mineralisation of organic matter, the formation of natural soil fertility, and water and temperature regimes, are the main issues highlighted in many, including Russian, works dated at the end of the 20th century as well as modern studies conducted within the framework of special scientific programmes and projects (Kazimirov, Morozova, 1973; Kazimirov et al., 1977; Manakov, Nikonov, 1981; Nikonov, Lukina, 1994; Zamolodchikov et al., 2005; Kudeyarov et al., 2007; Bobkova, Osipov, 2012; Osipov, 2013, 2015; Osipov, Bobkova, 2016; Bakhmet, 2018; Lukina et al., 2019, 2020). There are also estimates of the impact of different types of Russian forests on evaporation and water runoff (Karpechko, 2004; Onuchin, 2003; Karpechko et al., 2020; Kondrat’ev et al., 2020) and estimates of greenhouse gas fluxes at the levels of forest biogeocenosis and whole region. (Mamkin et al., 2019; Urban et al., 2019). However, these works did not assess the impact of biodiversity on climate regulation processes and forest functions at different spatial levels and in different time scales. We lack information on the combined effects of biodiversity components of different trophic levels and groups on ecosystem processes and functions (Gamfeldt et al., 2013; Mori et al., 2016; Van der Plas et al., 2016; Pugnaire et al., 2019).

There are few scientific works devoted to assessing the impact of the biodiversity of different types of forests on their climate-regulating functions, taking into account the combined effect of the diversity of biota at different trophic levels, and not only the species diversity of woody plants. Meanwhile, it is precisely these studies that are important for sustainable ecosystem management of forests in a changing climate. The studies in subtropical forests have shown that functional diversity of plants and heterotrophs, which accelerate the decomposition and cycles of nutrients, had a more significant impact on individual ecosystem functions and multifunctionality than the species diversity of woody plants alone (Schuldt et al., 2018). Thus, assessing the links between biodiversity and the climate-regulating functions of ecosystems is a major fundamental problem. Forests, like other ecosystems, are multifunctional, that is, they simultaneously perform many ecosystem functions that shape ecosystem services (Bradford et al., 2014; Byrnes et al., 2014; Manning et al., 2018; Van der Plas et al., 2018). All ecosystem functions are equally important and equitable, but the priority of ecosystem services is determined by humans, and the ecosystem–human relationships are need to be taken into account. The relationships can be either positive (synergy) or negative (conflicts/trade-offs) (Liang et al., 2016; Mori et al., 2017; Manning et al., 2018).

Russia pays much attention to the conservation of the global biodiversity of forests and performance of ecosystem functions by them. This country accounts for more than 20% of all world forest cover, including more than half of Earth’s boreal forests. The lands of the forest fund make up more than two thirds of the total land area of the country, and the share of area covered by forests (45.4%) is one of the highest in the world.

Typologies of Russian forests are based on the classification of vegetation (either on the basis of dominant or indicator species) and environmental conditions (types of habitat conditions) (Alekseev, 1925; Braun-Blanquet, Pavillard, 1925, cited in Mirkin, Naumova, 2009; Cajander, 1926; Sukachev, 1972; Pogrebnyak, 1955; Mirkin, Naumova, 2009). A significant step forward was the unified forest classification, which is based on the dominant approach, supplemented by ecological-cenotic and floristic analysis (Zaugol’nova, Morozova, 2006; Zaugol’nova, 2008). L.B. Zaugol’nova and V.B. Martynenko created an electronic identifier of forest types in European Russia (http://cepl.rssi.ru/bio/forest/index.htm). The key allows characterising the typological diversity of forests on the basis of the traditions of Russian forest phytocenology and international approaches to the classification of vegetation.

However, assessing the links between biodiversity and forest functioning requires taking into account the diversity of biota also of other trophic levels and groups. The most important scientific problem, which is currently of great-applied importance, is the assessment of the impact of biodiversity on the climate-regulating ecosystem functions of forests. To develop measures to adapt forests to climate change, we need to gain information on the combined effect of the diversity of biota of different trophic levels and groups on the completeness of the implementation of climate-regulating functions of forests and their adaptive potential.

Studies focused on the dependence of the climate-regulating functions of forests, representing different succession stages, on the level of their biodiversity will allow answering the question: is it really only ecosystem engineers, primarily dominant woody plants, that are important for adapting forests to climate change, or is it necessary to maintain and restore the biodiversity of forest ecosystems in general? Old-growth intact forests in Russia are refugia of biodiversity and a depository of soil carbon (East European …, 2004; European Russian Forests …, 2017; Smirnova et al., 2018). The importance of these Russian forests in climate regulation is difficult to overestimate; however, we still lack estimates of the combined effect of biodiversity components of different trophic levels and groups on the climate-regulating functions of old-growth intact forests.

The measures for adaptation to climate change include tree plantations consisting of different species; this approach is reasonable, but clearly insufficient. The climate-regulating functions are most fully implemented in old-growth intact forests, in which natural connections between various components of the biota have been preserved and which can serve as standards for comparisons with forests at different succession stages.

The performance of forest climate-regulating functions at the regional level depends on the forest ecosystem diversity and the contribution of different types of forests. The performance of climate-regulating functions at the ecosystem level is due to intra-ecosystem biodiversity, including the taxonomic and functional diversity of plants, animals, and microorganisms, as well as the structural biodiversity (micromosaics) of forests. This aspect of diversity characterises the diversity of habitats for biota of different trophic levels. For sustainable forest management under a changing climate, it is necessary to assess the relationships (synergy or trade-offs) between climate-regulating and other ecosystem functions of forests with different aspects of biodiversity in the course of natural development and under the combined impact of various natural and anthropogenic factors, including climate change, fires, and forest use regimes.

This article aims to raise a number of questions related to the assessment of the combined effect of the taxonomic and functional diversity of biota of different trophic levels and groups, as well as the structural diversity of forest ecosystems on their climate-regulating functions.

BASIC CONCEPTS OF THE PARADIGM OF FUNCTIONAL DIVERSITY AND BIODIVERSITY – FUNCTIONING LINKS

The need to address the problem of the impact of biodiversity on ecosystem functioning has led to the emergence of a new interdisciplinary research area – functional biodiversity. The functional biodiversity paradigm emphasises the active role of biota and its diversity in creating environmental conditions in ecosystems. Functional biodiversity is the diversity of different biota groups with specific roles in the community. The characteristic functional features of each species determine the biological mechanisms of their joint influence (the effect of the mixed composition of species) on individual functions and on the functioning of ecosystems as a whole (Cadotte et al., 2011; Scherer-Lorenzen, 2013).

The terms «ecosystem processes and properties», «ecosystem functions», «functioning», and «ecosystem services» are key in the concept of functional biodiversity (Naeem et al., 2002; Hooper et al., 2005; de Groot et al., 2010).

Ecosystem processes are physical, chemical, and biological events or actions that link organisms and their environment (Greenfacts https://www.greenfacts.org/glossary/def/ ecosystem-processes.htm) such as biomass production, litter degradation, nutrient cycles;

Ecosystem functions are the set of physical, biological, chemical, and other ecosystem processes that support the integrity and conservation of ecosystems (Ansink et al., 2008). Functions are intermediate links between processes and services.

Ecosystem services are the benefits that people receive from ecosystems (MEA, 2005), including providing services (fibre, wood, food, etc.), regulating services (erosion control, climate regulation, pollination, etc.), supporting services (soil formation, photosynthesis, etc.), and cultural services (recreational, educational, spiritual and religious, etc.).

Ecosystem functioning comprises events, processes, or properties of ecosystems influenced by biota.

To study the links between biodiversity and ecosystem functions and services, it is important to understand and evaluate the multifunctionality of ecosystems. Multifunctionality is the ability of ecosystems to perform simultaneously multiple functions and provide multiple services (Manning et al., 2018). Multifunctionality is divided into two levels: (i) multifunctionality of ecosystem functions, the assessment of which is aimed at fundamental research of biological, geochemical, and physical processes occurring in ecosystems; (ii) multifunctionality of ecosystem services, which is defined as the joint provision of a number of ecosystem services in response to a request from society.

Changes in biodiversity can lead to profound transformations in the functioning of ecosystems. To identify the effects of biodiversity on functions, it is necessary to take into account the influence of environmental factors and specific species. The most pronounced influence on the functioning of ecosystems is exerted by the so-called ecosystem engineers – organisms that create, modify, and maintain habitats, causing changes in the state of biotic and abiotic components that modulate directly or indirectly the availability of resources for other species (Jones et al., 1994, 1997). The ideas about powerful environment transformers – plants – dates back to the works of Braun-Blanquet (Braun-Blanquet, Pavillard, 1925, cited in Mirkin, Naumova, 2009), who proposed the concept of aedificator (from the French word meaning «builder») in relation to phytocenoses. V.N. Sukachev used it in works on phytocenology and biogeocenology. In terms of these works, an aedificator is a plant species, the presence of which in the biogeocenosis noticeably changes the ecological regimes – light, humidity, and temperature, chemical composition of soil, water, and atmoshphere – and determines the sets of subordinate species (Sukachev, 1928, 1935, 1964). The concepts of keystone species and ecosystem engineers appeared later. Although the scope of these concepts partially overlaps, they are far from identical. Keystone species include species, mainly of high trophic status, that have a disproportionate impact on the environment relative to their abundance (Paine, 1969).

Some species or functional groups make a greater contribution to the relationships between biodiversity and functions than others through specific functional traits that enable those species or groups to use resources more efficiently and to influence processes and functions (Eisenhauer et al., 2019). This phenomenon is called species identity.

THE INFLUENCE OF BIODIVERSITY ON FOREST FUNCTIONING

The question of how changes in biodiversity affect ecosystem processes and functions simultaneously remains unanswered. The existing studies aimed at assessing the impact of biodiversity on forest functioning include comparing monocultures and plantations of several tree species on permanent sample plots, conducting silvicultural experiments, and analysing natural gradients of forest biodiversity and forest inventory results. Studies of forest productivity and nutrient cycles show peculiar relationships between productivity and diversity, with differences between monocultures and mixed stands depending on the species composition and environmental conditions (Integrating …, 2016). Nevertheless, we require more in-depth studies of the biological mechanisms of the impact of coexisting species on the functioning of natural ecosystems. It will also be of practical importance for the creation of mixed (multi-species) forests that can fulfil a variety of functions.

The mechanisms by which increased biodiversity influences the functioning of ecosystems include the following (see Eisenhauer et al., 2019): (i) an increase in biotope space and number of ecological niches; (ii) an increase in the efficiency of resource use; (iii) an increase in the relationships between representatives of biota of different trophic levels; (iv) an increase in the effects of complementarity, which is manifested in the fact that a more diverse community consisting of specialised species that differ in structure and functions are able to use the available resources more efficiently than a single species that increases productivity and reduces the level of unused resources; and (v) enhancement of favoured effects, that is, positive influence of one species on the efficiency of another (the so-called nursery plants, or influence through provision of additional nutrients owing to symbiosis, etc.) that can also lead to increased resource efficiency and productivity.

Species richness is one of the main determinants of ecological processes in ecosystems. However, there is a lack of experimental studies on the gradients of the diversity of woody plants in natural conditions. The results of a study in the beech forests of Central Europe showed that an increase in the number of tree species from one to five had variable effects on different ecosystem processes. The diversity of arboreal species is negatively associated with the terrestrial biomass of communities (Jacob et al., 2010), while the relationships with the diversity of the herbaceous layer (Muller, 2003) and beetles (Sobek et al., 2009) is, on the contrary, positive. It is believed that the species identity of woody plants with special functional features and their abundance are the main determinants of these processes associated with the «dilution» of the influence of beech with an increase in the number of woody species. In addition, the covariance of some soil properties with tree diversity prevents clear recognition of the direct influence of species diversity on processes that are not mediated by environmental conditions. The results of existing studies allow us to conclude that the diversity of woody species partly explains the variation in some ecosystem functions and processes, alongside environmental factors and the influence of specific woody species (identity of woody species) (Pretzsch et al., 2020; Steckel et al., 2020).

Modern studies have shown positive relationships between tree species diversity and productivity and soil carbon stocks (Vesterdal et al., 2013). Many ecosystem functions and services, such as production of woody biomass, accumulation of soil carbon, forest plant species richness of the lower layers, and the presence of deadwood, are positively associated with each other and with the richness of woody species (Gamfeldt et al., 2013; Baeten et al., 2019). Experiments are underway to provide evidence of a link between tree species diversity and ecosystem functioning. They are designed to separate the effects of biodiversity, environmental conditions, and species identity. Such planting experiments are conducted as part of the European TreeDiv-Net programme (see, for example, Verheyen et al., 2016). The results indicate that woody plant diversity may be positively associated with pest resistance, carbon sequestration, and other processes and functions.

The abundance and diversity of plants and animals associated with trees are often positively associated with the diversity of woody plant species (see, for example, Poeydebat et al., 2020). Ecosystem functions and services are associated not only with environmental conditions, but also with the functional diversity of biota at different trophic levels. The influence of specific species (species identity) is also of great importance. However, from the standpoint of multifunctionality, it is obvious that a single species is not capable of performing many functions simultaneously, and there may be conflicts/trade-offs between individual services.

Biodiversity plays a key role in the sustainability of forests and, therefore, it becomes an essential element of strategies for adaptation to global climate and environmental changes and can be a tool for achieving management goals, such as providing simultaneously a variety of ecosystem services. This strategy should be implemented at the ecosystem level, starting with the creation of mixed-age stands, and at the landscape level through the development of multifunctional management of different types of forests. Forest mosaics with stands of different species can potentially maximise the provision of ecosystem services (Korotkov, 2017). Modern forestry with relatively short rotation plantations must take into account the linkages between biodiversity and functioning.

Given the above considerations, the studies aimed at understanding the role of biodiversity in the functioning of forests are becoming very demanding. There is a need to assess the consequences of species loss on forest functioning in the context of global climate change. Although some results have demonstrated positive relationships between tree species diversity and climate-regulating functions related to productivity and soil parameters (Schuldt et al., 2018), many studies have shown that the effect of individual species (species identity) is stronger than that of diversity (Tobner et al., 2016; Khlifa et al., 2017, 2020).

There are prominent knowledge gaps regarding the combined effects of biota diversity at different trophic levels on forest functions (Gamfeldt et al., 2013; Mori et al., 2016; Van der Plas et al., 2016; Pugnaire et al., 2019). This raises the question of the contribution of certain species and biodiversity in general to the variation of the climate-regulating functions of forests. Studies in subtropical forests showed that the functional diversity of plants and heterotrophs had a more significant effect on ecosystem functions than only the diversity of woody plant species (Schuldt et al., 2018). It is necessary to conduct such studies in boreal and temperate forests.

The results of some studies allow considering in general terms the influence of plants, animals, and microorganisms on ecosystem processes and functions of forests related to climate regulation.

The influence of plants on ecosystem processes and forest functions

Information on the environment-transforming effects of woody plant species continues to accumulate (Korotkov, 1991; Kuuluvainen, 1994; McCarthy 2001; Schliemann, Bockheim, 2011; Yamamoto, 2012; European Russian Forests …, 2017). The influence of woody plants as ecosystem engineers is manifested at the intra-ecosystem and ecosystem levels. Less disturbed forests create a mosaic of light, temperature, water, and soil regimes of ecosystems (McCarthy, 2001; East European …, 2004). This mosaic is a consequence of the following processes: (1) the formation of gaps in the forest canopy due to ageing and natural death of one or several nearby growing trees; (2) the formation of microsites created by tree falls, arising when the death of a tree is accompanied by a perturbation of the soil profile; this phenomenon forms specific «dump» microreliefs, including hillocks, depressions, and deadwood at different decomposition stages (Skvortsova et al., 1983; Ulanova, 2000; The afterlife of a tree, 2005; Bobrovsky, 2010). The heterogeneity of the environment formed as a result of generation flows in populations of tree species determines the presence in the ecosystems of the least disturbed forests with the maximum possible set of plant, animal, and fungal species and representatives of others kingdoms (East European …, 2004), which are embedded in the mosaic created by ecosystem engineers. In temperate forests of Russia, elements of microsites created by tree falls can occupy 10–90% of the biogeocenosis area (Karpachevsky et al., 1978; Ulanova, 2000).

With their specific functional features/traits, woody plants are the main contributors in biomass production, nutrient cycles, the presence and abundance of other species, etc. It was shown that 30 years after the creation of single-species plantations of woody angiosperms and gymnosperms, differences in calcium concentration in tree litter had led to profound changes in soil chemistry and fertility (Reich et al., 2005). The abundance of earthworms and their diversity is much higher in forests, the soils of which are rich in calcium. Hence, there is a direct link between vegetation, soil biota, and soil fertility. Changes in the species composition of dominant woody plants in forests, caused by management decisions or climate change, have an impact on certain ecosystem functions and services. The conducted studies were focused on the influence of woody plants on certain climate-regulating functions of forest types, including carbon and nitrogen cycles as well as soil fertility (Cornelissen et al., 2007a; Framstad, 2013; Laganiere et al., 2013; Vesterdal et al., 2013; Mueller et al., 2015; Orlova et al., 2016; Yatso et al., 2016). N.P. Remezov (1953, 1956) discussed the phenomenon of accumulation of biogenic elements in forest soils; he showed that the processes of elution in forests are opposed by the processes of accumulation of nutrients in the upper horizons of soils. Numerous works in recent decades have shown that plants affect biogeochemical cycles, fertility, and soil acidity (Binkley, Giardina, 1988; Hobbie, 1992; Van Breemen, Finzi, 1998; Augusto et al., 2002; Lukina et al., 2010; Hansson, 2011; Orlova et al., 2013).

The mechanisms by which plants influence the soil, which are analysed in the aforementioned works, include chemical weathering of rocks; redistribution of precipitation, light, heat, and nutrients; the input of nutrients via stem and crown waters; the effect on the decomposition and mineralisation of organic matter; the absorption of nutrients; and the creation of microsites by tree falls.

A number of results have been obtained from so-called common garden experiments on plantations formed by various woody plant species aged maximum 50–60 years. The ranking of woody plant species in decreasing acidification ability order is as follows: (Picea abies, Picea sitchensis, Pinus sylvestris) > (Abies alba, Pseudotsuga menziesii) > (Betula pendula, Fagus sylvatica, Quercus petraea, Quercus robur) > (Acer platanoides, Carpinus betulus, Fraxinus excelsior, Tilia cordata) (Augusto et al., 2002). These experiments and other studies confirmed the hypothesis that P. abies acidifies soils. However, it should be borne in mind that many plantations were formed on former agricultural lands, and the effect of trees on soil properties, including acidity, can change with age, and these changes can be non-linear, as shown for natural old-growth forests (Orlova et al., 2016).

The lower-layer plant species, whose composition changes during successions, also have a significant effect on the ecosystem functions of forests (Maes et al., 2020). An increase in the proportion of herbaceous plants in the composition of communities of taiga forests leads to an increase in the level of accumulation of soil carbon (Lukina et al., 2020). Functional types or groups of plants are identified based on certain functional features (chemical composition of litter, intensity of water absorption and transpiration, etc.) (Cornelissen et al., 2007b; Hedwall, Brunet, 2016; Vicente-Silva et al., 2016; Zhang et al., 2017; Anderegg et al., 2018).

In some studies, the functional groups of plants are regarded as their life forms (Salemaa et al., 2008). In Russian geobotany, the concept of ecological-cenotic groups is popular, which can in a certain sense correspond to functional groups of plants, because they are formed according to the principle of similarity of ecological and cenotic conditions in which they grow (Smirnova et al., 2004; Smirnov, 2007; Khanina et al., 2015).

The most important functional feature of plants is the litter quality (Cornelissen et al., 2007a). The quality of litter includes two aspects – secondary metabolites and nutrients – and is one of the most important factors determining the rate of litter decomposition (Aerts, 1997; Berg, 2000; Zhang et al., 2008). Litter quality refers to the diagnostic criteria of soil fertility, characterising the relationships between vegetation and soil (Orlova et al., 2011; Freschet et al., 2013, 2020; Orlova, 2013; Lukina et al., 2019); it considerably depends on plant species and individual genotypes (Hättenschwiler et al., 2005; Lang et al., 2009; Makkonen et al., 2012; Sundqvist et al., 2012). This means that the levels of nutrient intake and secondary metabolites in litter depend on the species and, accordingly, the chemical composition of plants and the contribution of various plant species to the composition of the plant community. Secondary metabolites, including phenolic compounds, protect plants (Dixon, Paiva, 1995) and make a significant contribution to the interaction of plants with the environment (Cheynier et al., 2013). We should highlight the prominent role of lignin, a three-dimensional phenolic polymer (Kovaleva, Kovalev, 2015; Kovalev, Kovaleva, 2016). As a component resistant to degradation, lignin affects the litter decomposition rate and, therefore, affects the mechanisms of interaction with soil biota and nutrient cycles. The rate of litter decomposition depends on the initial concentrations of nitrogen and other nutrients in it, both capable (potassium, phosphorus) and incapable (calcium, manganese) of retranslocation, within plants (the latter accumulate in aging organs), and also on several stoichiometric ratios: carbon/nitrogen (C/N), lignin/nitrogen, lignin/cellulose, etc. (Berg, 2000; Osono, Takeda, 2004; Lukina et al., 2017; Artemkina et al., 2018).

The influence of animals on ecosystem processes and forest functions

The role of animals in the functioning of terrestrial ecosystems, including forest ecosystems, has been assessed in many works (Gilyarov, 1951; Dinesman, 1961; Khodasheva, Eliseeva, 1970; Formozov, 1976; Striganova, 1980; Abaturov, 1984; Gilyarov, Krivolutsky, 1985; Mammals …, 1985; Herbivorous …, 1986; Toropova, 1994; Edwards et al., 1995; Bobrovsky, 2010; Veen, Olff, 2011; Hornov, 2013; Isaev et al., 2015; Shevchenko, 2016; Isaev et al., 2017; Kurek, 2019; Saikkonen et al., 2019; Evstigneev, Solonina, 2020; Nummi, Holopainen, 2020). These authors have studied the features of the impact of animal species, including ecosystem engineers, on biodiversity and soils. In the studies, animals were combined based on different features – a similar role in the trophic chain (grazing and detrital); behavioural features, that is, individual, reproductive, and social; and their importance in the economy, that is, fur-bearing animals and commercial ungulates. The impact of heterotrophs and their functions in biogeocenoses are diverse; a unified classification of the functional diversity of animals has not yet been developed. Because animals have a marked impact on the flows of matter and energy, they play a major, yet underestimated, role in the climate-regulating functions of forests.

There are several spatial levels of animal impacts: landscape, biogeocenotic, and intrabiogeocenotic (East European …, 1994, 2004).

Landscape level

Birds are one of the most prominent vertebrates in many habitats. They are found throughout the world; they are ecologically diverse and better known than other vertebrate groups (Grafius et al., 2017). Birds eat pests, pollinate plants, and disperse seeds (Whelan et al., 2015). Birds provide connectivity to both forests and other landscapes and contribute to the flow of matter and energy. Urban landscapes with high functional connectivity and biodiversity of vegetation are characterised by increased abundance of bird populations (Rosenfeld, 2012). The diversity of birds in forests increases the diversity of biotic connections between community components. However, the functioning of birds is closely related to the structural diversity of forests and the fragmentation of habitats (Galushin et al., 1998; Romanov, Evstigneev, 2016). The modern extinction of avifauna is caused by a decrease in the structural diversity of forests (Fridman et al., 2016).

Large-scale changes in the modern forest biogeocenotic cover are caused by beavers (Castor fiber). The environment-transforming effects produced by beavers are manifested at all spatial levels (Toropova, 1994; Smirnova, 1998; Wright et al., 2002; East European …, 2004; Zav’yalov et al., 2005; Aleynikov, 2010; Zav’yalov, 2013; Logofet et al., 2014, 2015). They make huts, burrows, dams, ponds, canals, paths, and glades in the modern forest cover of the valleys of small rivers and streams forming ecosystem complexes that consist of ponds, lowland swamps, waterlogged forests, and damp and fresh meadows. Hydromorphic and semi-hydromorphic ecosystems fundamentally change hydrological, thermal, and edaphic regimes of the valleys of small rivers and streams. These factors determine the enormous role of beaver landscapes in the optimisation and stabilisation of the local climate and in the formation of a stable hydrological regime of forest areas in general. This affects the realising the productive potential of forests and affects the structure and dynamics of the vegetation and animal populations. Thus, the activity of beavers maintains the main path of vegetation development in wetland and forest communities at the sites of existing settlements as well as in meadow and forest communities at the sites of abandoned settlements (Evstigneev, Belyakov, 1997). The use of the territory by beavers according to the «lea tillage» regulate cycles of vegetation development, which support the cenotic and floristic diversity of the vegetation cover of small river valleys. The mechanism for maintaining this diversity is based on the spatial distribution of vegetation types along the valleys of small rivers. Transformed by beavers ecosystems are actively used by terrestrial, semiaquatic, and aquatic animals (Nummi et al., 2011; Nummi, Holopainen, 2020). For example, beaver ponds serve as watering holes for birds and animals during droughts. In addition, these shallow water bodies provide favourable conditions for spawning of fish and amphibians and for living of teals, mergansers, and mallards (Balodis, 1990). Beaver glades serve as a source of food for wild ungulates, hares, mouse-like rodents, etc. Abandoned huts and beaver burrows can be used as permanent housing or temporary shelter by other animals: desmans, minks, vipers, spindles, forest ferrets, marsh turtles, etc. (Dezhkin et al., 1986).

Biogeocenotic and intrabiogeocenotic levels

According to the concepts developed based on the studies of natural ecosystems, large carnivores affect ecosystem functioning through trophic cascades by regulating the density of prey populations. However, at present, forest areas have been significantly transformed by humans, and the mechanisms of the influence of the remaining or reintroduced predators on the lower trophic levels are still poorly understood (Kuijperet al., 2016). It is believed that in anthropogenically transformed forests, the potential of such trophic cascades through regulation of population density is limited to unproductive ecosystems, where even a low number of predators can affect the density of prey, or to small areas of landscapes where predators can reach functional density. However, the action of trophic cascades through the behavioural responses of animals may be more significant and more widespread, because even a low density of predators affects the behaviour of ungulates. The effect of this mechanism has been demonstrated by the influence of lynx on roe reindeer in the Swiss Alps (Gehr et al., 2018), as well as the influence of wolf on roe reindeer, red reindeer, and wild boar in the Bialowieza National Park (Kuijper et al., 2013). The latter study was the first to show the influence of large carnivores (wolves) on reforestation and, accordingly, on climate regulatiing functions. It turned out that in areas with large tree debris (deadwood) that form physical obstacles the intensity of eaing the tree seedlings 0.1–2 m high by ungulates decreased because they are more likely to be overtaken by predators (wolves).

Ungulates, bison, representatives of the reindeer family (elk, European reindeer, reindeer, European roe reindeer, etc.), wild boars, badgers, and moles have a significant impact on climate-regulating functions of forests.

European bison (Bison bonasus) was an aedificator of forest ecosystems throughout almost the entire Holocene (Kalyakin, Turubanova, 2004; Cromsigt et al., 2018; Vasile et al., 2018; Lord et al., 2020). This species, together with other gregarious ungulates, created semi-open and open habitats in forests, formed highly productive pastures, fertilising the soil, and also ensured the stable existence of light-demanding flora (Smirnova, 2004; Shevchenko, 2016). Currently, the bison populations are small and protected by humans. Even the few existing bison populations markedly change the structure of forest communities. Bison eats herbaceous and woody plants; breaks down small trees; and creates trails, wallows and sites. A variety of microsites, differing in ecotopic conditions, ensures coexistence in a community of species that differ in environmental needs and life forms. For example, trees and shrubs damaged by bison often die, and gaps appear that provide sufficient light to support some meadow plant species in forests (Korochkina, 1969a; Kazmin, Smirnov, 1992). The high food plasticity of bison, oriented to the dominant plants of the vegetation cover, prevents competitive grasses from occupying the entire living space, freeing up habitats for other plants (Korochkina, 1969b; Tolkach, 1980). Bison creates disturbances of the ground cover; they support populations of weakly competitive juvenile plants in communities (Evstigneev, Solonina, 2016). One bison produces approximately 5,000 kg of excrement each year (Kholodova, Belousova, 1989). In this regard, bison grazing in forest biogeocenoses leads to a significant increase in the diversity of dung beetles and, consequently, to an increase in the content of nitrogen and available compounds of mineral nutrients of plants in the soil (Nemtsev et al., 2003; Barber at al., 2019).

Representatives of the reindeer family (Cervidae), which include elk (Alces alces), red reindeer (Cervus elaphus), reindeer (Rangifer tarandus), and European roe reindeer (Capreolus capreolus), among others, also have a powerful environment-transforming effect on forest ecosystems, but not always as powerful as that of bison. Bison grazing affects the abundance and species composition of the undergrowth of trees and shrubs as well as the species composition and cover of shrubs, grasses, mosses, and lichens; these effects determine the direction of the successions of modern forest communities (Korochkina, 1973; Vereshchagin, Rusakov, 1979; Gusev, 1983, 1986; Abaturov, Smirnov, 1992). For example, moderate grazing of reindeer in taiga forests increases the diversity of mosses, lichens, and vascular plants in the ground cover; the diversity of soil invertebrates; and the temperature of the soil (Suominen, Olofsson, 2000; Saikkonen et al., 2019). On the contrary, reindeer overgrazing decreases the cover and species diversity of vascular, primarily bushy, plants, mosses, and lichens, which are the most preferred food for reindeer in the winter (Hansen et al., 2007). Reindeer overgrazing can also reduce bird diversity due to destruction of nests (Rooney, 2001). Reindeer grazing has a significant effect on the undergrowth of woody plants, which defines the modern boundaries of the forest and tundra in Fennoscandia (Bognounou et al., 2018). The observed negative effects of the high density of herbivorous mammals emphasise the importance of predators as regulators at the highest trophic level for maintaining balance in ecosystems.

Wild boars (Sus scrofa) searching for soil invertebrates and underground plant organs disturb the ground vegetation cover (Sablina, 1955; Vereshchagin, Rusakov, 1979; Siemann at al., 2009; Gornov, 2013). In this case, soil disturbances are formed in different-sized areas. The soil exposed and mixed by wild boars is characterised by increased aeration, humidity, temperature, and high microbiological activity (Zlotin, Khodasheva, 1974; Gusev, 1986; Zav’yalova, 1997; Wirthner, 2011; Gornov, 2014). Boar excavations change the hardness of the soil, decreasing its density (Antonets, 1998). The special ecological conditions of the pores determine the dynamic processes in the communities (Evstigneev et al., 1999; Gornov, 2011, 2013). The following features of wild boars’ behaviour are important for the successional development of the ground vegetation: (i) formation of excavations, which are characterised by a bare substrate that is necessary for seed and vegetative reproduction of plants; and (ii) use of the territory according to the «lea tillage» system, in which excavations remain undisturbed for some time (Evstigneev et al., 1999). The latter is associated with a decrease in their feeding capacity. It is known that the invertebrate biomass in recently disturbed sites decreases 2–4 times (Gusev, 1986; Pakhomov, 2003) whereas the herbaceous plant’s biomass decreases 2–5 times (Smirnova, 1987). The invertebrate population usually recovers within 2–3 years (Gusev, 1986; Pakhomov, 2003) whereas vegetation recovers within 1–2 years (Kozlo, Stavrovskaya, 1974; Gornov, 2011). These recovery periods determine the cyclical development of vegetation spots on the disturbed areas and their spatial redistribution in the communities. Boar excavations are inhabited by numerous spiders, millipedes, carabids, earthworms, and other invertebrates. Their biomass and diversity are higher in these excavations than in the surrounding areas (Pakhomov, 2003).

An increase in the density of large phytophages in forest ecosystems affects not only grazing but also detrital food chains. The growing number of detritus as a result of the decomposition of excrement and animal corpses increases the diversity and density of coprophages and detritus feeders (earthworms, arthropods etc). The organisms intensify humus formation and increase soil fertilityand plant productivity throughout the growing season (Van Klink et al., 2020).

Badgers (Meles meles) markedly change the structure of forests. First, as a result of burrowing activity, these animals produce two types of soil disturbances. The first type involves the release of soil material during the cleaning of old burrows and the construction of new burrows. The individual earth mounds (butane) are 2–23 m². At the same time, badgers rise to the surface from 0.7 to 8.1 m³ of soil (Soloviev, 2007). On butanes, the availability of nutrients is significantly changed because the material ejected from the deep horizons of the soil is rich in potassium, calcium, magnesium, and available phosphorus but depleted in carbon and nitrogen (Kurek et al., 2014; Kurek, 2019). The second type of disturbances arise as a result of the trophic activity of badgers. In search of invertebrates and small vertebrates, as well as succulent underground parts of plants, badgers disturb the ground vegetation. The burrowing activity creates a mosaic of ground vegetation. The mosaic is represented by different microgroups: (i) a predominance of vegetatively immobile annuals and reactive juveniles, (ii) dominance of vegetatively mobile perennials of the reactive group, as well as with a significant participation of phytocenotically tolerant plants, and (iii) dominance of vegetatively mobile competitive perennials (Evstigneev, Solonina, 2020; Kurek, 2019). O.I. Evstigneev and O.V. Solonina (2020) consider this sequence of microgroups, which replaces each other in time, as a micro-succession. Competitive species are the driving force behind the development of microgroups. They gradually replace reactive and tolerant plants and can become dominant species of the herbaceous cover for a long time. However, the use of sites by badgers in a «lea tillage» system periodically interrupts these unidirectional micro-successions. The disturbances that badgers create and cyclical micro-successions maintain a multi-species composition in the herbaceous cover. The mechanism for maintaining this diversity works due to the spatial redistribution of microgroups with the dominance of plant species of different strategic types. Currently, due to overhunting, the badger has become an extremely rare and endangered species. A similar impact in forests is produced by foxes (Kurek et al., 2014). However, their burrowing activity is less intense than that of badgers (Formozov, 2010).

Moles (Talpa europaea) are insectivores that improve soil quality. By tunneling and moving soil material, they improve aeration and promote the penetration of humus both into deeper soil horizons and to the surface, increasing the availability of nutrients for plants. These underground mammals have low mobility; they live in a fairly constant environment characterised by the absence of light and stable temperature and humidity (Lacey et al., 2000). They are expected to be less susceptible to seasonal climatic fluctuations, unless these fluctuations lead to severe drought or freezing, which will dramatically increase soil hardness and reduce the availability of forage resources (soil animals) (Feuda et al., 2015). The burrowing activity of moles results in significant transformations of the horizontal structure of forests at the intrabiogeocenotic level. Moles make two types of passages in the soil: superficial and deep. When constructing deep passages, moles throw out the soil mass (Sklyarov, 1953). They create molehills, which are relatively small. The burrowing activity of moles results in the changes in microrelief. Moreover, the material inside the soil is mixed and the area of contact between the soil and air increases. The volume of soil involved in the release is approximately 10 m³ per hectare (Abaturov, 1984; Pakhomov et al., 1987). Molehills provide favorable conditions for many plant species, including trees (Tikhomirova, 1967; Zenyakin, Onipchenko, 1997). Over time, they are colonised by ants and other invertebrates (Tikhomirova, 1967). Mole tunnels attract vertebrates (amphibians, reptiles, small mammals) and invertebrates (earthworms, ground beetles, molluscs, spiders, etc.). In burrows, animals search for food, hide from enemies, and, in some cases, procreate (Nakonechny, 2013).

Birds and mammals are an active part of biocenoses, which determine the species composition of communities through the dissemination of diasporas: seeds, fruits, vegetative primordia, etc. (Levina, 1957; Udra, 1988; Ndiade-Bourobou et al., 2010; Holbrook, 2011; Evstigneev et al., 2017). The distance of dissemination of zoochorous plant species diasporas are determined by the biology and behaviour of animals – dissemination agents. There are three types of zoochoria: endozoochory, synzoochory, and epizoochory (Levina, 1957). Endozoochory is the spread of diasporas passed through the digestive tract of animals and then discarded with droppings. Synzoochory is the spread of diasporas associated with their dissemination by animals with the aim of storing them in pantries or eating them in nests. Epizoochory is the spread of diasporas attached or adhered to the body of animals. For example, bison, bears, elks, roe reindeer, capercaillies, and fieldfares spread diasporas mainly in endo- and epizoochoric ways. Squirrels, mice, voles, jays, nutcrackers, woodpeckers, nuthatches, and tits disseminate diasporas mainly in a synzoochoric manner. The survey works by Evstigneev et al. (2013, 2017) showed that massive dissimination of plant diasporas by animals are of great importance for the formation of phytocenoses, whereas single cases of dissimation over a long distance is of great importance for the expansion of the habitat of plant populations. Massive dissimination of diasporas of zoochoric plant species is implemented within the individual habitats of animals, whereas single cases od dissimation is implemented in the course of distant movements of animals (migrations). Thus, species diversity and high numbers of animals and birds contribute to the formation of diaspora flows both at the intercenotic and intracenotic levels. A decrease in the species diversity and number of animals limits the participation of zoochoric plant species in successions and weakens the intercenotic flows of diasporas.

Insects play a major role in the functioning of forest ecosystems. Given that insects and plants are the two largest taxa on Earth, it seems likely that interactions among these species will be crucial in shaping the response of many ecosystems to future climate changes. Insects affect nutrient cycles in ecosystems (Brussaard, 1998) accelerating them by the rapid transformation of phytomass to simple organic compounds, and regulating soil fertility. Insects influence the functioning and dynamics of plant populations and thus regulate their impacts on ecosystem processes (Brussaard, 1998). At a low population density, phytophagous insects remove 5%–7% of the phytomass of the leaf apparatus of trees; this action maintains the viability of plants. During outbreaks of mass reproduction and in cases of tree damage and death, there is renewal and transformation of the species composition. At the same time, caterpillar excrement acts as a fertiliser that contributes to the enhanced growth of herbaceous plants and reforestation. All of these processes affect the carbon cycle in forests. In many cases, phytophagous insects act in the forest ecosystem as components that determine the direction of successional processes, contributing to both acceleration and deceleration of forest ecosystem successions (Chernyshev, 1996).

In a balanced forest ecosystem, saproxylic insects, whose cycles are associated with deadwood of varying degrees of decomposition, regulate the density of woody plant populations based on the feedback principle, and also participate in food chains (Rafes, 1968; Demakov, 2000). The state of saproxylic populations is closely related to the state of tree stands, which are their food base and habitat and, therefore, some species can be indicators of the state of forest ecosystems (Lachat et al., 2012). In recent decades, the biology and ecology of key saproxylic insects from different functional groups have been studied in more detail to elucidate the mechanisms by which they maintain a stable state of forest ecosystems organised and supported by the life of their populations (Isaev, Girs, 1975; Isaev et al., 1981; Rozhkov, 1981, Lee et al., 2018). Large saproxylic species maintain a high biodiversity of other groups of invertebrates living together in wood (Buse et al., 2008a, 2008b). However, their interspecific relationships in forest ecosystems and changes in behavioural reactions under the influence of biotic and abiotic environmental factors remain understudied.

Coprophagous insects such as the dung beetle provide ecological functions and services through the physical management of the ecosystem (Nichols et al., 2008; Simmons, Ridsdill-Smith, 2011). In addition to consuming animal faeces, dung beetles scatter and bury them in the soil through burrowing and thus control a number of ecological processes, including nutrient cycling, soil aeration, and seed burial (Nichols et al., 2008; Simmons, Ridsdill-Smith, 2011). In this respect, dung beetles are considered ecosystem engineers (Boze et al., 2012) because their activities in the soil physically alter the environment in such a way that they increase the availability of resources for other organisms (Jones et al., 1994, 1997). There are examples of the activity of dung beetles promoting plant growth by mobilising nutrients in the soil (e.g., Bang et al., 2005; Nichols et al., 2008). This is due to the fact that beetles improve soil fertility by increasing nitrogen availability (Yokoyama et al., 1991). Dung beetles improve soil hydrological properties by increasing water infiltration and soil porosity while reducing surface water runoff (Brown et al., 2010). In the future, these ecosystem engineers should be able to alleviate water stress in plants, especially during droughts caused by changing rainfall patterns (Jonson et al., 2016).

Ants (Formicidae) produce special aboveground and underground structures – anthills (Zakharov, 1978). There are more than 10,000 ant species (Bolton, 1994), but with the use of DNA methods, estimates of species diversity are constantly changing (Schlick-Steiner et al., 2006). Ants are also referred to as ecosystem engineers changing the flow of energy and matter in terrestrial ecosystems (Finer et al., 2013). The overwhelming majority of ant species build nests in mineral soil and, therefore, they have a significant effect on soil properties (Hölldobler, Wilson, 1990). Building organic mounds on the soil surface makes ants susceptible to disturbances (Jurgensen et al., 2008). Forest fires and the use of heavy machinery for logging or preparing the soil for tree planting have led to the destruction of mounds and have had a negative impact on ant activity. The absence or low frequency of forest fires in Central and Northern Europe over the past centuries has led to an increase in the number of ants (Niklasson, Granstro, 2000). Wood ants (Formica rufa group) are key species in the European and Asian boreal and mountain forests (Hölldobler, 1960; Laine, Niemelä, 1980). They transfer organic matter from forest litter to their nests and from nests back to forest litter as well as from tree crowns to nests (Punttila and Kipelainen, 2009). Much attention has been paid to how ants of the genus Formica build mounds in boreal forests. Wood ants affect the abundance and distribution of many forest invertebrates and vertebrates in forests, forest litters, soils, and trees.

Inhabited anthills are characterised by a thin herbaceous cover; increased soil porosity, aeration, and temperature; and high microbiological activity (Dymina, 1985; Zryanin, 2003; Golichenkov et al., 2011; Dauber, Wolters, 2000), which affects the climate-regulating functions of forests. During humidification periods, anthills are well drained, whereas in dry periods they are strongly dried out (Kurkin, 1976). Anthill building contributes to the survival of the young generation of many plant species, including weakly competitive ones (Evstigneev, Rubashko, 1999; Dmitrienko, Ludwig, 2005). That is why special vegetation microgroups forming on anthills are floristically different from the surrounding cover. For example, in connection with the activity of F. rufa, the following microsites were distinguished: (i) dome of an active anthill, (ii) earthen rampart of an active anthill, (iii) dome of an abandoned anthill, and (iv) the shaft of an abandoned anthill (Rubashko et al., 2010). The appearance of these microsites increases the capacity of the habitat and the floristic diversity of the territory.

Invertebrates – soil saprophages

Matter and energy flows in forest ecosystems largely depend on the activity of the complex of invertebrate – saprophages associated with litter and soil. The diversity and structure of the saprophage complex provide a number of the most important ecosystem functions: they determine the direction and rate of litter decomposition and regulate soil fertility (Striganova, 1980; Ernst et al., 2009; Yang, Chen, 2009; Yatso, Lilleskov, 2016). Saprophages among soil invertebrates account for ≥ 80% of the total zoomass (Striganova, 2003).

The flow rate of dead organic matter entering the soil reaches at least 95% of the total amount of organic matter assimilated by producers (Begon et al., 1986). The source of carbon for soil saprophages is plant litter (including leaves, stems, and roots), root exudates of plants, and soil algae (Gleixner, 2013; Goncharov, 2014). In turn, the structure and functions of the complex of destructive saprophages depend on soil type, plant community composition, and climatic features.

All groups of soil saprophages have a significant effect on the cycles of carbon and nutrients and the formation of soil fertility. The example of earthworms, which often prevail among soil saprophages by biomass in deciduous forests, shows that their activity contributes to (i) fixation of soil carbon in the form of humus compounds (Kozlovskaya, Belous, 1967; Six et al., 2004; Jastrow et al., 2007; Schmidt et al., 2011; Lubbers et al., 2017); (ii) horizontal mosaic distribution of carbon in the soil due to horizontal migrations of worms in soil, movement of soil particles, and the formation of water-resistant coprolites, that is, a mixture of a mineral substrate and organic matter in which the carbon content increases by 30%–50% compared with the content in mineral soil horizon (Kurcheva, 1971; Tiunov, 2007; Kutovaya, 2012); and (iii) vertical mosaic distribution of carbon in the soil due to the transfer of organic matter from the upper to the lower soil horizons due to deep vertical migrations; this function is performed by the anecic earthworm group that was also shown by us on the example of old-growth mountain coniferous-broadleaf forests (Shevchenko et al., 2019).

However, there is still no unambiguous assessment of the effect of earthworm activity on soil carbon dynamics. Several studies have shown that carbon stocks decrease as a result of the activities of earthworms (Alban, Berry, 1994; Burtelow et al., 1998; Bohlen et al., 2004), while other studies have indicated that earthworms contribute to the accumulation of carbon in soils (Pulleman et al., 2005; Novara et al., 2015). Such opposing conclusions are probably due to the fact that in most works the complex of earthworms is considered holistically and does not take into account the role of individual functional types and groups: earthworms feeding on litter are primary humus formers (epigeic, epi-endogeic, and anecic) and endogeic worms feed in the soil, that is, secondary humus consumers (Perel’, 1979). In this regard, we face the need of differentiating the influence of different groups of earthworms in terms of soil carbon accumulation.

Initially, Bouché (1972) identified seven ecological categories of earthworms. They were subsequently combined into three main ones: epigeic, endogeic, and anecic. T.S. Perel’ (1979) singled out the morpho-ecological group represented by epi-endogeic earthworms.

Epigeic species are small, reaching 5 cm in length; these pigmented earthworms live in litter and rotting wood. They provide the primary decomposition of litter leached and secondary decomposition of polyphenolic, and other chemically resistant compounds preliminarily destructed by microorganisms. In the course of grinding plant material, the specific surface of the substrate increases hundreds of times together with its accessibility to microorganisms (Tiunov, Kuznetsova, 2000; Tiunov 2003, 2007). The succession of saprophages from the size group of the mesofauna (collembolans, oribatids) is accelerated simultaneously during the decomposition of organic substrates (Chernov, 1977). This results in the acceleration of tree litterfall decomposition, ammonification processes, nitrification, and consumption of ammonium and nitrates by plant roots (Kurcheva, 1971; Striganova, 1980; Byzov, 2005).

Epi-endogeic species include pigmented medium-sized earthworms (5–15 cm); they live in the forest litter and in the soil at shallow depths, recycle poorly decomposed tree litterfall, and actively mix it with the soil.

Endogeic species include unpigmented medium-sized earthworms (5–15 cm); they live in the soil, most often to a depth of 30–40 cm. They actively loosen the soil during horizontal and vertical migrations, feed on plant residues that have passed through the digestive tract of epigeic and epi-endogeic species, and get mixed with soil particles.

Anecic species include large earthworms (> 15 cm); only the anterior part of their bodies is pigmented. They live in the soil and, as a result of vertical migrations, they mix the soil layers and dig 1–8 m long passages, thus making the soil porous and filled with air and water that defines its fertility. Anecic earthworms are ecosystem engineers (Wright, Jones 2006; Tiunov, 2007; Zhang et al., 2016; Le Bayon et al., 2017). They affect both physical and chemical properties of the soil. The systems of cavities and passages dug by them exist much longer than the organisms that dig them and have a long-term effect on subsurface processes. These earthworms feed on plant debris on the soil surface, so the biomass of anecic earthworms largely determines the rate of litter decomposition in forests.

A global meta-analysis showed that the presence of not only epigeiс and anecic earthworms, but also endogeic species decrease the content of organic matter in the litter horizon, with the strongest effect exerted by anecic earthworms (Huang et al., 2020). Moreover, even earthworms of the same group can have different impact on soil characteristics (Van Groenigen et al., 2019).

Assessment of the functional diversity of soil saprophages is very important because the completeness of the implementation of ecosystem functions of forest communities depends on the diversity of functional groups. However, until now, the isolation of functional groups has not been justified clearly even within such a group of macrosaprophages such as earthworms, although it is obvious that worms of different ecological categories (Bouche, 1972) or morpho-ecological groups (Perel’, 1979) have different effects on soil properties (as shown above). Since 2000, the term «functional group» has become synonymous with the designation of the main ecological categories (groups) of earthworms. At the same time, some authors consider this approach to be incorrect and argue that the ecological groups of earthworms are not identical to functional groups (Bottinelli, Capowiez, 2020). The main arguments are: (i) the classification of ecological groups is based on the morphology and anatomy of earthworms and reflects, first of all, how the worms have adapted to the environment, but not how they affect it; and (ii) the number of functional groups of worms is probably greater than the number of ecological groups, because the impact on soil properties even within the same ecological group often differs (Van Groenigen et al., 2019).

Consequently, the question of the functional classification of large soil saprophages remains open. To elucidate the influence of invertebrates on soil properties, we need to use a combination of methods: direct measurements of the influence of individual species, which requires the development of standard research protocols and the formation of open databases (Bottinelli, Capowiez, 2020); molecular genetic research, because until now a number of even widespread saprophages with pronounced polymorphisms has no definite systematic status (Shekhovtsov et al., 2020); and a stable isotope method to study trophic relations in the soil, including in the field – this method opens up large horizons in ecosystem ecology (assessment of trophic niches, food resources, substance flux). However, the use of a larger number of isotope pairs (in addition to carbon and nitrogen isotopes) is still methodologically restricted: some isotopes are poorly fractionable, namely sulphur isotopes, and we still lack data on hydrogen isotopes (Tiunov, 2007; Potapov et al., 2014; Makarov et al., 2019, etc.). The latest studies are focused on isotopic composition of nitrogen and carbon of amino acids of dipteran larvae (Pollierer, 2020), epigeic and endogeic earthworms (Potapov et al., 2019) that makes it possible to differentiate their trophic resources. In particular, these studies indicate major roles of plant litter in the nutrition of epigeic earthworms, and of soil organic matter and microorganisms in the nutrition of endogeic earthworms (Potapov et al., 2019).

In a broad sense, forest ecologists increasingly agree that all diversity levels of soil invertebrates – taxonomic, phylogenetic, ecological, and functional – serve as the basis for the multifunctionality of ecosystems (Tresch et al., 2019) and that increased functional diversity of soil biota complements enhances ecosystem functions; in other words, synergy effects outweigh trade-off effects (Bender et al., 2016).

Diversity in the soil biome makes a significant contribution to the inverse relationships between soil functions and climatic parameters (Wall, 2012). Assessment of the role of the biodiversity of soil fauna in adapting forests to climate change is considered in the context of ecological soil engineering (Bender et al., 2016) and the need to form and maintain climate-smart soils (Paustian et al., 2016).

It is crucial to study soil biodiversity effects on greenhouse gas emissions from soils as well as carbon storage in soils to assess carbon cycles. Soil fauna activities can trigger feedback mechanisms that either enhance or mitigate the impact of climate change (Lubbers et al., 2013; Crowther et al., 2016). It is also assumed that the diversity of soil macrosaprophages (earthworms, isopods, molluscs, and millipedes) can serve as an important mechanism for limiting greenhouse gas emissions from soil (Lubbers et al., 2020). Greater functional diversity of soil macrofauna leads to an intensification of litter decomposition and the fixation of carbon in the soil in the form of humic compounds as a result of the trophic activity of soil saprophages, as well as bioturbation, which is realised primarily by earthworms. In the absence of macrofauna, especially earthworms, litter is decomposed by the representatives of saprotrophic meso- and microfauna; however, this leads to intensification of carbon dioxide emission from the soil surface, and only the activity of earthworms reduces these losses (Frouz et al., 2013).

The diversity of soil macrofauna has a significant impact on the biogeochemical cycle of nutrients (Coulis et al., 2015; Filser et al., 2016; Sauvadet et al., 2017) and plant productivity (Van Groenigen et al., 2014). The biodiversity of soil macrofauna directly correlates with the diversity of vegetation (Tresch et al., 2019) and affects the diversity of soil microorganisms, namely bacteria and fungi (Cao et al., 2018).

As a result of the interaction between macrofauna and microbial community, nitrogen cycles are significantly affected by soil invertebrates. Forty percent of all nitrogen absorbed by plants is processed by soil saprophages. Digestive enzymes of the intestines of earthworms activate mineralization processes in soil – ammonium transforms into nitrites and nitrates (Bityutskiy et al., 2007). In addition, the annual death of earthworms in soils alone increases the nitrogen pool by 24 g/m², which is comparable to the annual dose of mineral nitrogen fertilisers (100–200 kg nitrogen per hectare). Earthworm biomass, which contains 65%–75% protein, quickly decomposes in soil, but nitrogen is not washed out as quickly as it is bound by microorganisms (Lee, 1985; Makeschin, 1997). Earthworms decrease emissions of nitrous oxide (N₂O), a gas with a strong greenhouse effect (Drake, Horn, 2006; Nebert et al., 2011).

Earthworms decrease the C/N ratio threefold compared to tree litterfall. This is associated with the direct and indirect influence of earthworms on the mineralisation and humification of organic matter (Striganova, 1968). There is experimental evidence of a significant decrease in the C/N ratio under the influence of different morpho-ecological groups of earthworms; this decrease is not limited to forest soils. For epi-endogeic earthworms, this fact was established in vermicompost (Talashilkar et al., 1999); for endogeic earthworms, this fact was established in agricultural fields (Sandor, Schrader 2007; McDaniel et al., 2013). According to our published data (Geraskina, 2020), the influence of different morpho-ecological groups of earthworms on the nitrogen content and the C/N ratio is multidirectional in the horizons of their activity – the nitrogen content increases whereas the C/N ratio decreases.

The role of earthworms as ecosystem engineers is also significant regarding regulation of the water regime. During horizontal and vertical migrations, they form up to 50% of the pore space of the soil (biopores). This area affects water migration and gas diffusion in the soil and outside of it (Lee, Foster, 1991; Lubbers et al., 2011) and prevents surface runoff and water erosion of soil by increasing the vertical transport of atmospheric waters (Schneider et al., 2018).

Influence of fungi on ecosystem processes and forest functions

Fungi are one of the main components of forest ecosystems and contribute significantly to the overall biodiversity. Most of mycobiota are soil dwellers (Carlile et al., 2001). The mycelial structure helps them search for new nutrient substrates in this heterogeneous environment with maximum speed and efficiency (Carlile et al., 2001; Gadd, 2007; Chernov, Marfenina, 2010). This adaptation has allowed fungi to become one of the main components of microbial cenoses in the soil; they perform various ecological functions (decomposition of almost any organic compounds, formation of symbiosis with plants, participation in soil formation, etc.).

According to some estimates, the total number of fungal species can reach several million, but no more than 10% of these species have been described and documented (Hawksworth, Lücking, 2017). Despite the fact that most fungal species are unknown, the main functions that they perform in biocenoses have been identified. Fungi play an important role in the life of forest ecosystems: they are the main agents for processing organic matter in the soil and forest litter, forming ectomycorrhiza on tree roots, phytoparasites, or antagonists of parasites (Frąc et al., 2018). Mycorrhizal mycobiota support almost all vascular plants (including trees), saprotrophic fungi decompose organic residues (including wood lignin), and entomopathogenic fungi control the number of invertebrates. An one third of all microbial biomass is represented by ectomycorrhizal fungi in forest soils; together with colonised roots, they secrete half of all soluble soil organic matter (Högberg, Högberg, 2002).

Soil fungi are divided into three functional groups: biological and ecosystem regulators and species involved in the decomposition of organic matter and transformation of compounds (Swift, 2005; Gardi, Jeffery, 2009). Fungi regulate not only diseases and the number of parasites, but also the growth of other organisms (Bagyaraj, Ashwin, 2017). Thus, mycorrhizal fungi have a positive effect on plant growth, activating the absorption of mineral nutrients. In addition, fungi are involved in the nitrogen cycle (Kurakov, 2003) and production of hormones; they play an important role in the stabilisation of organic matter and the decomposition of plant debris (Jayne, Quigley, 2014; Baum et al., 2015; El-Komy et al., 2015; Treseder, Lennon, 2015). The functioning of soil fungi depends on the diversity and composition of plant communities. On the other hand, fungi affect plant growth through mechanisms such as mutualism and parasitism, and through the effect on the cycles of mineral nutrients and their bioavailability (Wardle, 2002; Wagg et al., 2014; Hannula et al., 2017).

The prokaryotic (bacteria and archaea) soil component has been studied much more thoroughly than the fungal component, despite the fact that mycobiota account for most (up to 98%) of the entire microbial biomass (Ananyeva et al., 2010; Polyanskaya et al., 2020). However, unlike bacteria, whose taxonomic position (especially in the case of high taxonomic ranks) cannot always be associated with specific ecological functions, relationships between the taxonomic position of fungi and their functions in forest ecosystems can be established. Specifically, representatives of the taxon Glomeromycetes are the main generators of endomycorrhiza of herbaceous plants. Most representatives of the order Boletales form ectomycorrhiza with trees. The large genera Penicillium, Aspergillus, and Trichoderma are saprotrophs that decompose cellulose and starch. The genera Armillaria, Phellinus, Cronartium, and Laetiporus are tree parasites. Members of order Polyporales are wood destructors of living and dead trees. (Frąc et al., 2018). The overall diversity (alpha diversity) of fungi is related to the state of ecosystems and responds to soil degradation and deforestation, among other factors (Chaer et al., 2009).

In recent decades, the biodiversity of soil fungi has been actively determined using molecular biological methods, primarily metabarcoding and metagenomics (Semenov, 2019). High-throughput sequencing of fungal phylogenetic markers in DNA preparations extracted from soil allows a much more complete variety of fungi to be covered than microscopic and fungal cultivation methods. Constantly updated taxonomic databases (such as SILVA) allow for the most complete assessment of the taxonomic structure of the fungal community based on genetic information.

Functionally, fungi are closely related to earthworms. The influence of earthworms on fungi is multifaceted: trophic – selective consumption of fungi; phoric – the transfer of spores and mycelium fragments in horizontal and vertical directions along the soil profile; metabolic – the effect of biologically active compounds of the earthworm digestive tract on the viability of fungi (there are known effects of both inhibition and activation of the development of fungal spores); and metabiotic – the creation of fundamentally new ecological niches for fungi during the burrowing activity of large saprophages (creation of pores, cavities, changes in the chemistry of the environment, isolation of coprolites, etc.). At the same time, the pool of fungi determines the activity of earthworms due to the trophic value of fungal biomass and the fungal production of biologically active substances (Byzov, 2005; Spurgeon et al., 2013; Kurakov et al., 2016; Cao et al., 2018).

Overall, fungi in forest ecosystems have a direct effect on climate-regulating functions through the conversion of carbon compounds, including mineralisation of lignin, cellulose, and soil organic matter, and an indirect effect through the redistribution of nutrients and regulation of the activity of plants and invertebrates. Thus, the assessment of not only the taxonomic, but also the functional diversity of biota of different trophic levels and different trophic groups is one of the most important scientific problems. Indeed, if it is not solved, it will be impossible to assess the impact of biodiversity on the climate-regulating functions of forests and to develop approaches to adapting forests to climate change.

Structural biodiversity

One of the most important aspects of forest diversity is structural diversity. The structural diversity of forest ecosystems reflects the diversity of habitats and, accordingly, the general level or the potential of forest biodiversity and the prospective for the implementation of ecosystem climate-regulating functions. Researchers have used different approaches and criteria to assess the structural diversity of forests: deadwood decomposition stages, the ratio between dead and living trees, the size (diameter) of trees, the proportion of old trees, and the richness of tree species in the dominant canopy and undergrowth, among others (Storch et al., 2018).

In our studies, we have interpreted structural diversity as a mosaic of forest cover. The basic concepts of the mosaic nature of forest biogeocenoses and their individual components widely known in Russia and abroad include the concept of elementary soil areals by V.M. Friedland (1986), the concept of forest parcella by N.V. Dylis (1969), the concept of coenobiotic microgrouping by L.G. Ramensky (1938), and the concept of tessera by H. Jenny (1958) and by L.O. Karpachevsky (1977).

According to V.M. Friedland (1986), sporadically spotted homogeneous elementary soil areals are widespread in the forest. The background of these soils is complicated by spots of limiting structural elements, which are not considered elementary soil-geographical objects. Because they owe their origin to biota, they are formed by recent disturbances, including windfalls; they exist due to woody plants. The entire complex of limiting structural elements and homogeneous background represents the forest soil cover in successional development, whereas homogeneous soil background reflects only a part of the soil forest cover.

N.V. Dylis (1969) substantiated the identification of the level of a parcella in forests as an intrabiogeocenotic unit. The concept of a parcella was further developed, including in the works of CEPF RAS employees (East European …, 1994, 2004; Smirnova, 1998). In forests with a pronounced mosaic structure, parcellas are represented by gaps, which are formed at the site of the fall of one or several trees and are at different overgrowth stages. The elements of such a mosaic differ based on environmental conditions, including light, temperature, precipitation, and element cycles (Muscolo et al., 2014). At present, large areas are dominated by forests in which this mosaic is not expressed; the belowcrown and betweencrown spaces are often distinguished with only some elements of microsites created by tree falls.

There is an entire class of forest gap mosaic models. Their development presumably began in 1969, and the JABOWA model is considered the parent. These models are popular among ecologists because they allow assessing and predicting all stages of the development of woody plants; the dynamics of their productivity due to changes in the light availability, soil temperature, precipitation; and the impact of global changes on forests (Bugmann, 2001; Chumachenko, Smirnova, 2009; Zhu et al., 2014), including the carbon balance (Chambers et al., 2013). A number of modern experimental studies have focused on assessing the effect of gap sizes in forests on soil biota, which regulates nitrogen and carbon cycles. Researchers have concluded that an optimal microclimate and substrate formed at the border of the gaps increases the microorganism biomass and activity. The biomass of microbes and fungi that form endomycorrhiza and determine soil respiration negatively correlate with gap sizes (Scharenbroch, Bockheim, 2007; Schliemann, Bockheim, 2014).

In gaps of Norwegian old-growth spruce forests, soil waters were characterised by higher C/N ratios compared to soil waters under the forest canopy. Large wood residues formed as a result of tree felling serve as a source of dissolved organic matter (Nygaard et al., 2018). It is estimated that 20%–40% of organisms in forest ecosystems live off the decaying wood of living, weakened, or dead trees for their life cycle (Bauhus et al., 2018). It is recognised that deadwood not only serves as a habitat, but also plays an important role in the carbon and hydrological cycles, in the cycles of mineral nutrients, and is a key structural component influencing ecosystem processes. Deadwood at different decomposition stages serves as an important habitat for many species and groups of soil fauna. The underestimation of deadwood can lead to incorrect estimates of not only the taxonomic, but also the functional diversity of soil fauna (including earthworms), insects, and other invertebrates, especially in boreal forests (Goncharov, 2014; Geraskina, 2016; Ashwood et al., 2019; Jacobsen et al., 2020).

Parcellas are not homogeneous: there are mosaics of different types of trees at different ages. The soil and plant components of the gap parcella are also mosaic – it is possible to identify the trunks of previously felled trees overgrown with mosses and shrubs, spots of mounds and depressions, green moss, lichen, small grasses, tall grasses, fern components of biogeocenoses, and undergrowth of woody plants, all of which have a specific effect on soils (Lugovaya et al., 2013; Geraskina et al., 2020).

A tessera is another unit of cover. H. Jenny (1958) identified a tessera as a landscape element, including soil, vegetation, and soil biota. For a tessera, he suggested taking a unit of those area and shape, which are convenient for certain purposes. L.O. Karpachevsky (1977) regarded a tessera as a soil component of a parcella. Within a tessera, he distinguished microzones: near-trunk, middle, and edges of the crown. L.G. Ramenskiy (1938) identified coenobiotic microgroups related to the plant component resulting from the specific effect of certain plants on environmental conditions. These plants, «having settled and occupied a certain area, so strongly influence the regimes of the air and soil environment that they largely displace some other species and get along with the species for whom these newly created conditions are favorable» (Ramenskiy, 1971).

Thus, for V.M. Friedland, an elementary soil areal reflects only a part of the soil forest cover. For L.G. Ramensky, a microgroup refers only to the plant component, and for L.O. Karpachevsky, a tessera includes only the soil component. For N.V. Dylis, a parcella includes atmosphere, vegetation, soil, and soil biota. However, L.O. Karpachevsky (1977) was the first to prove that the soil component of a parcella can be divided into microzones. Therefore, we can conclude that the parcella is not an elementary unit of biogeocenosis. In addition, in modern forests, the parcel structure is far from always expressed, because most of the forests have been significantly transformed. The tessera defined by H. Jenny includes all elements of the biogeocenosis, but it has artificial boundaries.

In our opinion, an elementary unit of the forest biogeocenotic cover, as an elementary provider of ecosystem functions, must meet three requirements (Orlova, 2013). Specifically, this unit must: (i) be indivisible, the smallest, and basic; (ii) include all interrelated components of the biogeocenosis (atmosphere, soil, vegetation, soil biota); and (iii) form a base level in the hierarchy of spatial units of the forest biogeocenotic cover. To study the vegetation–soil relationships that regulate ecosystem functions, it was proposed to consider the elementary biogeoareal as an elementary unit of the biogeocenotic cover, at the level of which these relationships are formed (Orlova, 2013). Areas, forms, boundaries, as well as the name of the elementary biogeoareal are determined by the dominant plant species – that is, by plant component – which corresponds to the concept of coenobiotic microgrouping by L.G. Ramensky. We consider the elementary biogeoareal to be a structural and functional unit of the forest biogeocenotic cover. It is an elementary provider of ecosystem functions, including the climate-regulating functions of forests. To assess the structural diversity of forests in each study object, it is advisable to single out the dominant elements of the forest cover mosaic in the canopy (in the belowcrown space of different tree species) and in betweencrown space and/or gaps, including different felling stages. The hierarchy of spatial units of the forest biogeocenotic cover, in our opinion, can represent the following series: elementary biogeoareals (EBGA) – biogeocenosis – geochemically coupled biogeocenoses – drainage basins (see also Orlova, 2013).

Thus, assessing the impact of structural diversity on the climate-regulating functions of forests is a scientific problem of great practical importance. Analysis of the current state of the problem indicates that it is necessary to assess more thoroughly the impact of the structural diversity of forest ecosystems on the climate-regulating functions.

RELATIONSHIPS BETWEEN CLIMATE- REGULATING FUNCTIONS: ASSESSMENT BY ENVIRONMENTAL MODEL COMPLEXES

It is important to assess not only the climate-regulating functions of forests with different levels of biodiversity, but also the relationships between these functions. The modern computer simulation methods allow assessing individual ecosystem functions. These models differ at the spatial level: local individual-based models (Seidl et al., 2012), landscape models (Scheller et al., 2007), and regional and national models (Kurz et al., 2009; Beringer et al., 2011; Kuz’mina et al., 2017). However, these tools focus on individual ecosystem functions of forests (Rämö, Tahvonen, 2017; Pukkala, 2018), and only the approach developed in the last decade is based on the integration of models within decision support systems (Wikström et al., 2011; Borges et al., 2014) and allows their comprehensive assessment. Modern experimental studies often involve simulation models of forest ecosystems to compare different forest management strategies (Shanin et al., 2011; Söderbergh, Ledermann, 2003). Such models are usually developed as the basis for decision support systems in the forestry sector. These models are multifunctional and include empirical stand growth models, individual-based models, biogeochemical models, matrix models of carbon balance, dynamic global vegetation models, and landscape and regional models.

Trade-offs and synergies between the climate-regulating functions of different types of Russian forests can be forecast using the existing Russian models applicable to forest ecosystems: FORRUS-S, EFIMOD-ROMUL-SCLISS, ILHM, ILLM, and COSMO.

The FORRUS-S simulation model (Chumachenko et al., 2003) belongs to the class of ecological and physiological models simulating the processes of establishment, growth, and death of trees. It is designed to predict the dynamics of wood and non-wood resources, the recreational potential of forests, and biodiversity dynamics.

The EFIMOD Forest Ecosystem Model System (Komarov et al., 2003) is an individual-based system that includes the ROMUL soil organic matter dynamics model (Chertov et al., 2001) and the SCLISS statistical soil climate generator (Bukhovets, Komarov, 2002), and it is associated with the BioCalc phytodiversity assessment model (Khanina et al., 2007). The model system is individual-based; there are two aspects of interaction between neighboring trees: shading and competition for available soil nitrogen. The system consists of a number of blocks: a model of the growth of biomass for an individual tree, a spatial model of the stand with a detailed imitation of competition between trees, and a ROMUL soil organic matter dynamics model (Komarov et al., 2017; Chertov et al., 2017a, 2017b), which describes the dynamics of mineralisation and humification of organic matter depending on its chemical composition and hydrothermal conditions in the soil. A new submodel for calculating the production of tree biomass (Shanin et al., 2019) makes it possible to take into account the influence of a complex of factors associated with climate change (changes in air temperature, soil moisture, concentration of carbon dioxide in the air). In addition, new submodels of competition for light (Shanin et al., 2020) and soil nitrogen in forms accessible to plants (Shanin et al., 2015) make it possible to more accurately analyse the spatial structure of the stand. The model also provides tools that allow simulating various kinds of disturbances (fires, selective and clear cuttings, etc.).

The Hydrological model for the formation of runoff from the catchment or ILHM (Institute of Limnology Hydrological Model) (Kondrat’ev, Shmakova, 2005; Kondrat’ev, 2007) is intended to calculate hydrographs of meltwater and rainwater runoff from a catchment area, as well as the water level in a reservoir.

The Model for the formation of biogenic load on water bodies or ILLM (Institute of Limnology Load Model) (Kondrat’ev, 2007) was designed to solve problems related to the quantitative assessment of runoff and removal of nutrients from the forest catchment under influence of different forest management regimes and climate change.

The Climatic version of the COSMO model is intended to assess the impact of changes in forest cover in the central regions of the European territory of Russia on regional meteorological conditions (Kuz’mina et al., 2017).

Trade-offs and synergies between the functions/services of an ecosystem can be assessed using the integrated platforms presented above and other mathematical models. The existing approaches for simulation modelling will make it possible to assess the relationships (synergy and/or trade-offs) between the climate-regulating functions of forests and to predict the dynamics of these functions in the natural development of forests characterised by different levels of biodiversity, and with the combined impact of climate change, fires, and management regimes on forests.

There are two main approaches to measure multifunctionality. The first approach implies averaging or summing functions: the sum of the standardised values of each measured function is used (Mouillot et al., 2011; Maestre et al., 2012). The second approach is threshold; it takes into account the number of functions that crossed a threshold or a range of thresholds, usually expressed as a percentage of the highest level of functions observed in a particular study (Gamfeldt et al., 2008; Byrnes et al., 2014). This approach can be improved by using weights that determine the importance of a particular function (Lukina et al., 2020). Trade-offs and synergies between functions can be analysed based on the magnitude and sign of the coefficient of the correlation between their normalised values.

APPROACHES TO CONSERVATION AND RESTORATION OF BIODIVERSITY

Global climate changes will continue. They are difficult to predict or even unpredictable; therefore, mitigation of the effects of climate change and adaptation to them becomes the most important strategic goal of states. An approach to preserve the remaining intact or almost intact forests with their existing levels of biodiversity and to restore biodiversity (rewilding) in those disturbed forests, where possible, will contribute to the adaptation of forests to climate change and mitigation of its impact, because owing to biodiversity, these ecosystems are self-regulating.

Due to long-term nature management and past anthropogenic impacts, self-regulated ecosystems cannot always be restored, especially in cases of endangered species, namely large herbivores (Smirnova, Toropova, 2017; Cromsigt et al., 2018; Vasile et al., 2018; Smirnova, Geraskina, 2019; Lord et al., 2020) or soil fauna (Bulavintsev, 1979; Butt, 2008; Moradi et al., 2018; Geraskina, 2019). In these cases, another approach is acceptable – human intervention. Obviously, long-term land use that disrupted natural processes and ecosystem dynamics on Earth, which was determined by biodiversity, has led to the formation of anthropogenic landscapes that can function sustainably only with human participation. At the same time, moderate anthropogenic disturbances have resulted in landscape mosaics of species habitats; periodic disturbances are crucial to preserve these landscape mosaics (Feurdean et al., 2018). Therefore, we share a concept that takes into account both approaches: restoration of biodiversity, where possible, and human intervention, where necessary (Van Meerbeek et al., 2019).

The scientific literature also discusses a binary approach to biodiversity conservation and the use of forest ecosystem services: segregation or integration (Krauss, Krum, 2013; Abruscato et al., 2020). To develop strategies and measures for the conservation and restoration of forest biodiversity as a mechanism for forest climate-regulating functions, the key issue is the choice of management approaches that allow preserving biodiversity and providing all forest ecosystem services, including supportive (soil formation, conservation and maintenance of biota habitats, etc.), regulatory (regulation of climate, hydrological regime, etc.), productive (provide wood, fibres, non-wood products), and cultural (educational and scientific purposes, recreation, health rehabilitation, aesthetic pleasure). Although the Russian forests are divided according to their intended purposes (production, protection, reserve), not only in reserve, but in all protective (not only protected areas) and production forests, forests of high conservation value should be preserved and allocated (Jennings, 2005; Yanitskaya, 2008). In our opinion, the most acceptable tactic is the joint use of elements of both approaches in the same territory/in the same zone. However, such planning at different spatial levels requires special studies aimed at justifying the approaches, the application of which will allow conserving and restoring biodiversity at different levels for adaptation to climate change.

The genetic diversity of plants plays the most important role in the preservation and restoration of forests and their adaptation to climate change. The European Forest Genetic Resources Programme (EUFORGEN) was launched in 1994 based on a resolution adopted in 1990 at the first Ministerial Conference on the protection of forests in Europe (http://www.euforgen.org). This programme promotes the conservation and sustainable use of forest genetic resources in Europe as an integral part of sustainable forest management and implementation of relevant provisions of the Convention on Biological Diversity. The forests of Russia are characterised by a poor species composition of forest stands but significant intraspecific variability, which is formed under conditions of ecologically heterogeneous vast areas of forest-forming species (CPSR, 2017). A unique feature of the Russian forest fund is the preservation of vast areas of boreal forests with a native or intact population genetic structure. For the study, conservation, and rational use of forest genetic resources in Russia, it is necessary to implement the programme on forest genetic resources developed by Russian geneticists (CPSR, 2017; Concept …, 2020). This endeavour requires, along with other tasks, the study of natural mechanisms for maintaining the optimal (adequate to forest growing conditions) genotypic composition of populations and the influence of various natural and anthropogenic factors on it. It is also necessary to conduct experimental, analytical, and simulation studies to substantiate the maximum permissible volumes and rules for the placement of plantation forests, which guarantee the preservation of the population structure and genetic potential of forest-forming species. We also need to systematise Russian and international achievements in the field of forest genetics, genomics, breeding, and biotechnology to modernise and integrate programmes for forest varietal seed production and plantation forestry. Finally, methods for clonal micropropagation of valuable tree species should be developed.

Due to overhunting and poaching, many animals have been extinguished or have become extremely rare in forests. In this regard, developed and implemented programmes are aimed not only at their protection, but also at their reintroduction. A successful example is the restoration of beaver populations. A nature conservation ideology is based on the restoration of highly productive ecosystems characteristic of this region by the gradual return of preserved large animals to their original ranges, where they were previously completely exterminated by humans. Rewilding is a new strategy for conserving natural resources; it has gained immense popularity in the modern world. It is aimed at restoring natural processes with minimal human intervention (Donlan et al., 2006; Zimov et al., 2012; Van Klink, 2020). The restoration of European bison populations in forest ecosystems is one of the most striking modern examples of reintroduction, and bison populations are now being restored in several countries (Cromsigt et al., 2018; Vasile et al., 2018; Lord et al., 2020). There are several examples of the recovery of populations of large animals in Russia. The Russian Ministry of Natural Resources is actively working on the resettlement of bison. The participants of this programme specifically include protected natural areas such as Bryansky Les (Bryansk region) and Kaluzhskiye Zaseki (Kaluga region), as well as the national parks Orlovskoe Polesie (Oryol region), Smolenskoe Poozerie (Smolensk region), and Ugra (Kaluga region). The total number of bisons in these territories at the end of 2018 was more than 650. The goal of the Pleistocene Park project in the Republic of Sakha (Yakutia) is to create a highly productive ecosystem imitating the mammoth steppes that dominated Eurasia in the late Pleistocene (pleistocenepark.ru). The park is inhabited by bison, Yakut horses, moose, musk oxen, reindeer, and other ungulates. Experimentation has led to the dominance of grasses and cereals in many plots and an increase in the soil carbon content (Zimov, 2005).

However, modern forest ecosystems are highly fragmented and disturbed by long-term (since the beginning of the Holocene) anthropogenic impact (Smirnova et al., 2020) as a result of the loss of biota groups that formed various functional blocks that regulated, among other things, the density of ecosystem engineers. Therefore, these ecosystems are subject to opposite effects – biodiversity decreases rather than increases and habitat degrades. Overgrazing of reintroduced reindeer has resulted in soil depletion and loss of land cover biodiversity in Norway (Hansen et al., 2007). Incompleteness of the coprophage complex and grazing of reintroduced bison do not increase soil fertility; indeed, bison excrement accumulates and remains for a long time at the initial decomposition stages in the Orlovskoye Polesie National Park (Geraskina et al., 2018). An increase in the density of beavers in North America has led to large-scale environment-transforming effects and a decrease in the diversity of grasses and trees. Therefore, they are called ecosystem pests (Hacker, Coblentz, 1993). The literature indicates that even the unintentional settling of ecosystem engineers such as earthworms (European species) in the forests of North America, where they form highly dense populations, decreases the biological diversity and density of other groups of meso- and microfauna. According to the authors, this is due to habitat homogenisation (Migge-Kleian, 2006; Ferlian et al., 2018) and a decrease in the biodiversity of the vegetation cover. The consumption of forest litter by worms is a serious obstacle to the development of undergrowth of tree species (Hale et al., 2006; Frelich et al., 2019). The above examples of the negative impact of ecosystem engineers on biological diversity may indicate a strong disturbance of forest ecosystems, the absence of important functional biota groups that regulate the density and behaviour of animals at different trophic levels, as well as a low level of structural diversity of ecosystems, that is, a weakly expressed mosaic of habitats for different species and groups of animals in managed forests.

Restoration of biological, including structural, diversity in modern forests is possible due to the inclusion in forestry practice of some measures aimed at enhancing the heterogeneity of the forest: staggered and hollow felling combined with planting multi-species forest trees with multi-chess placement of planting material and thinning. Sanitary felling with the preservation of undergrowth of coniferous and broad-leaf tree species can be conducted in the drying-out foci of forest stands (Methodical …, 1989; Korotkov, 2016, 2017; Zagidullina, Drobyshev, 2017). Gaps in the forest canopy can be created by ringing the bark of trees (injection of arboricides is also possible), causing them to dry out, as well as by artificial fallouts, when the formation of gaps is combined with the formation of microsites created by tree falls, which enhance the heterogeneity of the soil cover (East European …, 1994). It is also important to preserve – and maintain through haymaking – in-forest clearings for moderate grazing of livestock or wild animals. These actions markedly increase biodiversity and also create favourable conditions for the development of light-demanding species of trees and shrubs at the forest edges. Therefore, the breeding and cultivation of forest trees should be aimed at the formation of a group-glade type of plantations (groups of trees alternate with glades and blanks) (Korotkov, 2016, 2017).

A combination of forestry practices should aim to restore the species and structural diversity, as well as the diversity of habitats. The latter endeavour, now called retention forestry, includes the preservation of some deadwood and stumps to ensure the existence of fungi, different groups of invertebrates, and hollow-nesting birds, among others, and making gaps for light-demanding flora, pollinating insects, birds, and mammals. It is considered to be the most promising forestry methodology (Storch et al., 2019; Augustynczik et al., 2020; Gustafsson et al., 2020).

CONCLUSION: SCIENTIFIC ISSUES AND KNOWLEDGE GAPS

 Assessment of the combined effect of diverse biota of different trophic levels on the climate-regulating functions of forests of different types, taking into account their structural diversity, is a fundamental scientific problem of great practical importance. Such assessments are essential for the conservation and restoration of biodiversity, which underpins the mechanisms of adaptation of forests and society to climate change.

The suitable object for assessing the impact of biodiversity on climate-regulating functions is intact old-growth forests, in which the natural mechanisms of the joint functioning of many species are still preserved.

To assess the impact of biodiversity on the climate-regulating functions of forests, it is necessary to undertake the following tasks:

• Design and develop functional classifications of biota of different trophic levels and to assess their functional diversity in different types of forest biogeocenoses, landscapes (geochemically coupled biogeocenoses), and whole catchment.

Because the level of functional biodiversity determines the completeness of the implementation of climate-regulating ecosystem functions, the functional classification of biota belonging to different trophic levels is crucial. Thus, the classification of plants by the quality of litter makes it possible to assess the influence of plants on such climate-regulating functions as the regulation of the cycles of carbon, nitrogen, and other elements of mineral nutrition, and the formation of soil fertility. At the same time, as our studies (Lukina et al., 2018) have shown, to assess the influence of woody plants on the climate-regulating functions of forests, including their water regime formation function, we need to take into account characteristics of woody plants such as density and the length of crowns. These properties determine the amount of precipitation penetrating under the canopy and the volume of soil water. To assess the impact of plants on ecosystem functions, it is necessary to develop classifications using the corresponding specific properties/traits of plants.

The question of the functional classification of vertebrates remains open. However, it needs to be addressed to clarify the influence of different functional groups on the functioning of forests and, therefore, on the possibility of adapting forest ecosystems to climate change.

We still lack direct field measurements and open experimental data on invertebrate soil saprophages in forests. It is necessary to develop standard protocols for the study of soil biodiversity in structurally diverse ecosystems such as forest ecosystems, taking into account the maximum set of mosaic elements that make up the forest cover, including deadwood, which, as a rule, is not taken into account when conducting field research. We also lack quantitative estimates of the contribution of different elements of the spatial mosaic to the diversity, density, and total saprophage biomass. The issues of the functional affiliation and even the taxonomic status of invertebrates remain relevant. They need to be addressed because many forms differ in the horizons of trophic and locomotor activity in the soil. Most of the forest fungal species remain unknown. Therefore, these studies need to be intensified. In recent decades, the biodiversity of soil fungi has been actively determined using molecular biological methods, primarily metabarcoding and metagenomics. To study trophic relations in soil, it is important to use both molecular genetic methods and methods of stable isotopes.

• Comparatively assess the influence of species identity and the combined influence of the diversity of biota of different trophic levels and groups on the completeness of the implementation of climatic regulation functions at different spatial levels in different time scales

To solve this problem at the level of the biogeocenosis type, it is advisable to conduct studies in monodominant and polydominant forests. These forests represent different succession stages, but they function in similar climatic conditions and are formed at similar positions of the landscape and on parent rocks of similar mechanical and chemical composition. The completeness of the implementation of functions can be assessed by comparing with forests at the most advanced succession stages, that is, old-growth intact forests.

Assessment of the contribution of individual forest types to the functioning of geochemically coupled landscapes and whole catchments using remote sensing methods will make it possible to assess the impact of biodiversity on the climate-regulating functions of forests at different spatial levels. Mapping the climate-regulating functions of forests is a critical scientific task of great value both for investigating the links between biodiversity and these functions, and for designing decision support systems. Development and application of simulation mathematical modelling methods and designing model platforms will make it possible to assess the relationships between functions and to predict the dynamics of climate-regulating functions.

• Assess the impact of the structural diversity of forests on climate regulation functions

Highly mosaic and structurally complex forests are characterised by a higher level of resilience to stresses, including climate change. However, climate-regulating functions of forests, as a rule, are assessed without taking into account their structural diversity. Therefore, the task of assessing the links between the structural diversity of forests and the completeness of their performance of climate-regulating functions is necessary.

• Develop mathematical model platforms to assess and to predict the relationships between ecosystem functions and services

To simulate the ecosystem functions and services, a large number of computer models have been developed. They differ in structure, the degree of detail, spatial and temporal discreteness, etc. Professional attitudes to the structure and patterns of the functioning of forest ecosystems and improvement of computer and programming technologies and mathematical apparatuses have created the prerequisites for the widespread use of ensembles of ecological models for a comprehensive assessment of a wide range of ecosystem services and the relationships between them. Accordingly, it is necessary to develop methodological approaches as well as software and hardware solutions to design a platform for integrating a system of models (Grabarnik et al., 2020).

• Develop concepts and approaches to forest management, taking into account the conservation and restoration of biodiversity and ecosystem functions of forests

Developing approaches to forest management at different spatial levels remains a crucial scientific problem taking into account the conservation and restoration of biodiversity and the provision of all ecosystem services. From our point of view, binary approaches (segregation or integration) are conditional. The most promising are the approaches that take into account the combination of segregation and integration approaches, conservation, and creation of self-regulating forest ecosystems by restoring biodiversity.

To conserve forest genetic resources in Russia, it is necessary to implement the programme on forest genetic resources.

Long-lasting transformation of forests by humans contribute to the dominance of some species and the elimination of others. Human activities associated with land-use change and the destruction of predators can be a direct or indirect cause of an imbalance between populations of different species, a phenomenon that leads to overgrazing of herbivores in forests, outbreaks of mass reproduction of insects, or mass drying of woody plants as a result of fungal diseases (i.e., when creating monodominant forest plantations). We need to develop mechanisms for regulating the size of populations of different species to create managed forests that can adapt to climate change, that is, capable of self-regulation.

ACKNOWLEDGEMENT

The study was conducted within the framework of the state CEPF RAS assignment AAAA-A18-118052590019-7. The authors are deeply grateful to the reviewer V.N. Korotkov for a number of valuable comments and additions, which made it possible to improve the content and structure of the article.

REFERENCES

Abaturov B.D., Mlekopitayushchie kak komponent ekosistem (na primere rastitel’noyadnyh mlekopitayushchih v polupustyne) (Mammals as a component of ecosystems (on the example of herbivorous mammals in a semi-desert), Moscow: Nauka, 1984, 288 p.

Abaturov B.D., Smirnov K.A., Formirovanie drevostoev na vyrubkah v lesah s raznoj plotnost’yu populyacii losya (Formation of stands in clearings in forests with different densities of elk populations), Byulleten’ MOIP. Otdel biologicheskij, 1992, Vol. 97, No 3, pp. 3-12.

Aerts R., Nitrogen partitioning between resorption and decomposition pathways: a trade-off between nitrogen use efficiency and litter decomposibility? Oikos, 1997, Vol. 80, No 3, pp. 603-606.  

Alban D.H., Berry E.C., Effects of earthworm invasion on morphology, carbon, and nitrogen of a forest soil, Appl. Soil Ecol., 1994, Vol. 1, pp. 243-249.

Alejnikov A.A., Sostoyanie populyacii i sredopreobrazuyushchaya deyatel’nost’ bobra evropejskogo na territorii zapovednika «Bryanskij les» i ego ohrannoj zony (The state of the population and the environment-transforming activity of the European beaver on the territory of the reserve “Bryansk Les” and its buffer zone, Candidate’s biol. sci. thesis), Tol’yatti: Institut ekologii Volzhskogo bassejna RAN, 2010, 22 p.

Alekseev E.V., Tipy ukrainskogo lesa. Pravoberezh’e (Types of Ukrainian forest. Right bank), Kiev, 1925, 64 p.

Anan’eva N.D., Polyanskaya L.M., Stol’nikova E.V., Zvyagincev D.G., Sootnoshenie biomassy gribov i bakterij v profile lesnyh pochv (Fungal to bacterial biomass ratio in the forest soil profile), Izvestiya Rossijskoj akademii nauk. Seriya biologicheskaya, 2010, No 3, pp. 308-317.

Anderegg W., Konings A., Trugman A.Yu.K., Bowling D., Karp D., Pacala S., Sperry J., Sulman B., Can plant functional diversity buffer forest ecosystem responses to drought? Geophysical Research Abstracts, 2018, Vol. 20, p. 8935.

Ansink E., Hein L., Hasund K.P., To value functions or services? An analysis of ecosystem valuation approaches, Environmental Values, 2008, Vol. 17, No 4, pp. 489-503.

Antonec N.V., Osobennosti royushchej deyatel’nosti dikogo kabana v poemnyh dubravah lesostepnoj i stepnoj zon (Features of burrowing activity of wild boar in the floodplain oak forests of the forest-steppe and steppe zones), Zapovidna sprava v Ukraїni, 1998, Vol. 4, Issue 2, pp. 18-24.

Artemkina N.A., Orlova, M.A., Lukina N.V. Micromosaic Structure of Vegetation and Variability of the Chemical Composition of L Layer of the Litter in Dwarf Shrub–Green Moss Spruce Forests of the Northern Taiga, Contemporary Problems of Ecology, 2018, Vol. 11, No 7, pp. 754-761.

Ashwood F., Vanguelova E.I., Benham S., Butt K.R., Developing a systematic sampling method for earthworms in and around deadwood, Forest Ecosystems, 2019, Vol. 6, No 33, pp. 1-12.

Augusto L., Ranger J., Binkley D., Rothe A., Impact of several common tree species of European temperate forests on soil fertility, Annals of Forest Science, 2002, No 59, pp. 233-253

Augustynczik A.L.D., Gutsch M., Basile M., Suckow F., Lasch P., Yousefpour R., Hanewinkel M., Socially optimal forest management and biodiversity conservation in temperate forests under climate change, Ecological Economics, 2020, Vol. 169, Article: 106504.

Baeten L., Bruelheide H., van der Plas F., Kambach S., Ratcliffe S. …, & Scherer‐Lorenzen M., Identifying the tree species compositions that maximize ecosystem functioning in European forests, Journal of Applied Ecology, 2019,  Vol. 56, No 3, pp. 733-744.

Bagyaraj D.J., Ashwin R., Soil biodiversity: role in sustainable horticulture, Biodivers. Hortic. Crops., 2017, Vol. 5, pp. 1-18.

Bahmet O.N., Zapasy ugleroda v pochvah sosnovyh i elovyh lesov Karelii (Carbon storages in soils of pine and spruce forests in Karelia), Lesovedenie, 2018, No 1, pp. 48-55.

Balodis M.M., Lesoekologicheskie aspekty bobrovogo hozyajstva v antropogennom landshafte (Forest-ecological aspects of beaver farming in the anthropogenic landscape), Lesovedenie, 1990, No 1, pp. 29-37.

Bang H.S., Lee J.-H., Kwon O.S., Na Y.E., Jang Y.S., Kim W.H. Effects of paracoprid dung beetles (Coleoptera: Scarabaeidae) on the growth of pasture herbage and on the underlying soil, Applied soil ecology, 2005, Vol. 29, pp. 165-171.

Barber N.A., Hosler S.C., Whiston P., Jones H.P., Initial Responses of Dung Beetle Communities to Bison Reintroduction in Restored and Remnant Tallgrass, Natural Areas Journal, 2019, Vol. 39, No 4, pp. 420-428.

Bauhus J., Baber K., Müller J., Dead Wood in Forest Ecosystems, Oxford: Oxford University Press, 2018, pp. 1-16.

Baum C., El-Tohamy W., Gruda N., Increasing the productivity and product quality of vegetable crops using arbuscular mycorrhizal fungi: a review, Scientia Horticulturae, 2015, Vol. 187, pp. 131-141.

Begon M., Harper J.L., Townsend C.R., Ecology: Individuals, Populations and Communities, Oxford: Blackwell Scientific Publications, 1986, 1068 p.

Bender S.F., Wagg C., van der Heijden M.G., An underground revolution: biodiversity and soil ecological engineering for agricultural sustainability, Trends in ecology & evolution, 2016, Vol. 31, No 6, pp. 440-452.

Berg B., Litter decomposition and organic matter turnover in northern forest soils, Forest Ecology and Management, 2000, Vol. 133, pp. 13-22.

Beringer J., Hutley L.B., Hacker J.M., Neininger B. Patterns and processes of carbon, water and energy cycles across northern Australian landscapes: from point to region, Agricultural and Forest Meteorology, 2011, Vol. 151, No 11, pp. 1409-1416.

Binkley D., Giardina Ch., Why do trees affect soils? The Warp and Woof of tree-soil interactions, Biogeochemistry, 1998, No 42, pp. 89-106.

Bityuckij N.P., Solov’eva A.N., Lukina E.I., Olejnik A.S., Zavgorodnyaya Yu.A., Demin V.V., Byzov B.A., Ekskrety dozhdevyh chervej – stimulyator mineralizacii soedinenij azota v pochve (Stimulating effect of earthworm excreta on the mineralization of nitrogen compounds in soil), Pochvovedenie, 2007, No 4, pp. 468-473.

Bobek B., Perzanowski K., Energy and matter flow through ungulates, In: Forest Ecosystems in Industrial Regions, W. Grodziriski, J. Weiner, P.F. Maycock (Eds.), Berlin: Springer-Verlag, 1984, pp. 121-125.

Bobkova K.S., Osipov A.F., Krugovorot ugleroda v sisteme “fitocenoz-pochva” v chernichno-sfagnovyh sosnyakah srednej tajgi Respubliki Komi (Carbon cycling in system “phytocenosis-soil” in bilberry-sphagnum pine forests of the middle taiga (Republic of Komi), Lesovedenie, 2012, No 2, pp. 11-18.

Bobrovskij M.V., Lesnye pochvy Evropejskoj Rossii: bioticheskie i antropogennye faktory formirovaniya (Forest soils in European Russia: biotic and anthropogenic factors in pedogenesis), Moscow: Tovarishhestvo nauchnyh izdanij KMK, 2010, 359 p.

Bognounou F., Hulme P.E., Oksanen L., Suominen O., Olofsson J., Role of climate and herbivory on native and alien conifer seedling recruitment at and above the Fennoscandian tree line, Journal of Vegetation Science, 2018, Vol. 29, No 4, pp. 573-584.

Bohlen P.J., Pelletier D.M., Groffman P.M., Fahey T.J., Fisk M.C., Influence of earthworm invasion on redistributionand retention of soil carbon and nitrogen in northern temperate forests, Ecosystems, 2004, Vol. 7, pp. 13-27.

Bolton B., Identification guide to the ant genera of the world, Harvard University Press, 1994, 222 p.

Borges J.G., Nordström E.M., Garcia-Gonzalo J., Hujala T., Trasobares A. (Eds.), Computer-based tools for supporting forest management. The experience and the expertise world-wide, Report of Cost Action FP 0804 Forest Management Decision Support Systems (FORSYS), Sveriges Lantbruks universitet. Institutionen för skoglig resurshushållning, Umeå, 2014.

Bottinelli N., Capowiez Y., Earthworm ecological categories are not functional groups, Biology and Fertility of Soils, 2020, pp. 1-3.

Bouche M.B., Lombriciens de France: écologie et systématique, Paris: Institut national de la recherche agronomique, 1972, 671 p.

Boze B.G., Hernandez A.D., Huffman M.A., Moore J., Parasites and dung beetles as ecosystem engineers in a forest ecosystem, Journal of insect behavior, 2012. Vol. 25, No 4, pp. 352-361.

Bradford M.A., Wood S.A., Bardgett R.D., Black H.I., Bonkowski M., Eggers T., Jones T.H., Discontinuity in the responses of ecosystem processes and multifunctionality to altered soil community composition, Proceedings of the National Academy of Sciences, 2014, Vol. 111, No 40, pp. 14478-14483.

Brown J., Scholtz C.H., Janeau J.-L., Grellier S., Podwojewski P., Dung beetles (Coleoptera: Scarabaeidae) can improve soil hydrological properties, Applied soil ecology, 2010, Vol. 46, pp. 9-16.

Brussaard L., Soil fauna, guilds, functional groups and ecosystem processes, Applied soil ecology, 1998, Vol. 9, No 1-3, pp. 123-135.

Bugmann H., A review of forest gap models, Climatic Change, 2001, Vol. 51, pp. 259-305.

Bulavincev V.I., Formirovanie naseleniya melkih pozvonochnyh na territoriyah, narushennyh otkrytymi razrabotkami poleznyh iskopaemyh (Formation of the population of small vertebrates in territories disturbed by opencast mining of minerals), Zoologicheskij zhurnal, 1979, Vol. 58, No 3, pp. 1884-1887.

Burtelow A.E., Bohlen P.J., Groffman P.M., Influence of exotic earthworm invasion on soil organic matter, microbial biomass and denitrification potential in forest soils of the northeastern United States, Appl. Soil Ecol., 1998, Vol. 9, pp. 197-202.

Buse J., Ranius T., Assmann T., An endangered longhorn beetle associated with old oaks and its possible role as an ecosystem engineer, Conservation Biology, 2008a, Vol. 22, pp. 329-337.

Buse J., Zabransky P., Assmann T., The xylobiontic beetle fauna of old oaks colonised by the endangered longhorn beetle Cerambyx cerdo Linnaeus, 1758 (Coleoptera: Cerambycidae), Mitt. Dtsch. Ges. Allg. Angew. Entomol., 2008b, Vol. 16, pp. 109-112.

Butt K.R., Earthworms in soil restoration: lessons learned from United Kingdom case studies of land reclamation, Restoration Ecology, 2008, Vol. 16, No 4, pp. 637-641.

Byhovec S.S., Komarov A.S., Prostoj statisticheskij imitator klimata pochvy s mesyachnym shagom (Simple statistical simulator of soil climate with a monthly step), Pochvovedenie, 2002, No 4, pp. 443-452.

Byrnes J., Lefcheck J.S., Gamfeldt L., Griffin J.N., Isbell F., Hector A., Multifunctionality does not imply that all functions are positively correlated, Proceedings of the National Academy of Sciences of the United States of America, 2014, Vol. 111, No 51, pp. e5490.

Byzov B.A., Zoomikrobnye vzaimodejstviya v pochve (Zoomicrobial interactions in soil), Moscow: GEOS, 2005, 213 p.

Cadotte M.W., Carscadden K., Mirotchnick N., Beyond species: functional diversity and the maintenance of ecological processes and services, Journal of Applied Ecology, 2011, Vol. 48, pp. 1079-1087.

Cajander A.K., The theory of forest types, Acta Philosophica Fennica, 1926, Vol. 29, pp. 1-108.

Cao J., Wang C., Dou Z., Liu M., Ji D., Hyphospheric impacts of earthworms and arbuscular mycorrhizal fungus on soil bacterial community to promote oxytetracycline degradation, Journal of hazardous materials, 2018, Vol. 341, pp. 346-354.

Cardinale B.J., Matulich K.L., Hooper D.U., Byrnes J.E., Duffy E., Gamfeldt L., … & Gonzalez A., The functional role of producer diversity in ecosystems, American journal of botany, 2011, Vol. 98, No 3, pp. 572-592.

Carlile M.J., Watkinson S.C., Gooday G.W., Fungal diversity, The fungi, Academic Press, 2001, 2nd ed., pp. 11-84.

Chaer G., Fernandes M., Myrold D., Bottomley P., Comparative resistance and resilience of soil microbial communities and enzyme activities in adjacent native forest and agricultural soils, Microbial ecology, 2009, Vol. 58, pp. 414-424.

Chambers J.Q., Negron-Juarez R.I., Marra D.M., Di Vittorio A., Tews J., Roberts D., … & Higuchi N., The steady-state mosaic of disturbance and succession across an old-growth Central Amazon forest landscape, Proceedings of the National Academy of Sciences, 2013. Vol. 110, No 10, pp. 3949-3954.

Chernov I.Yu., Marfenina O.E., Adaptivnye strategii gribov v svyazi s osvoeniem nazemnyh mestoobitanij (Adaptive strategies of fungi in connection with the development of terrestrial habitats), In: Paleopochvy i indikatory kontinental’nogo vyvetrivaniya v istorii biosfery (Fossil soil and indicators of continental weathering in the history of the biosphere), Moscow: PIN RAN, 2010, pp. 95-111.

Chernova N.M., Ekologicheskie sukcessii pri razlozhenii rastitel’nyh ostatkov (Ecological successions during decomposition of plant residues), Moscow: Nauka, 1977, 199 p.

Chertov O.G., Komarov A.S., Nadporozhskaya M.A., Bykhovets S.S., Zudin S.L., ROMUL — a model of forest soil organic matter dynamics as a substantial tool for forest ecosystem modelling, Ecological Modelling, 2001, Vol. 138, pp. 289-308.

Chertov O., Komarov A., Shaw C., Bykhovets S., Frolov P., Shanin, V., … & Shashkov M., Romul_Hum–a model of soil organic matter formation coupling with soil biota activity. II. Parameterisation of the soil food web biota activity, Ecological Modelling, 2017a, Vol. 345, pp. 125-139.

Chertov O., Shaw C., Shashkov M., Komarov A., Bykhovets S., Shanin V., …  & Zubkova E., Romul_Hum model of soil organic matter formation coupled with soil biota activity. III. Parameterisation of earthworm activity, Ecological Modelling, 2017b, Vol. 345, pp. 140-149.

Cheynier V., Comte G., Davies K.M., Lattanzio V., Martens S., Plant phenolics: recent advances on their biosynthesis, genetics, and ecophysiology, Plant physiology and biochemistry, 2013, Vol. 72, pp. 1-20.

Chumachenko S.I., Korotkov V.N., Palenova M.M., Politov D.V., Simulation modelling of long-term stand dynamics at different scenarios of forest management for conifer — broad-leaved forests, Ecol. Modeling., 2003, Vol. 170, pp. 345-361.

Chumachenko S.I., Smirnova O.V., Modelirovanie sukcesionnoj dinamiki nasazhdenij (Modeling of succession dynamics of forest stands), Lesovedenie, 2009, No 6, pp. 3-17.

Cornelissen J.H., Lang S.I., Soudzilovskaia N.A., During H.J., Comparative cryptogam ecology: a review of bryophyte and lichen traits that drive biogeochemistry, Annals of botany, 2007a, Vol. 99, No 5, pp. 987-1001.

Cornelissen J.H.C., van Bodegom P.M., Aerts R., Callaghan T.V., van Logtestijn R.S.P., … & Team M.O.L., Global negative vegetation feedback to climate warming responses of leaf decomposition rates in cold biomes, Ecological Letters, 2007b, Vol. 10, pp. 619-627.

Coulis M., Fromin N., David J.F., Gavinet J., Clet A., Devidal S., … & Hättenschwiler S., Functional dissimilarity across trophic levels as a driver of soil processes in a Mediterranean decomposer system exposed to two moisture levels, Oikos, 2015, Vol. 12, No 10, pp. 1304-1316.

Cromsigt J.P., Kemp Y.J., Rodriguez E., Kivit H., Rewilding Europe’s large grazer community: how functionally diverse are the diets of European bison, cattle, and horses? Restoration Ecology, 2018, Vol. 26, No 5, pp. 891-899.

Crowther T.W., Todd-Brown K.E.O., Rowe C.W., Wieder W.R., Carey J.C., Machmuller M.B., … & Bradford M.A., Quantifying global soil carbon losses in response to warming, Nature, 2016, Vol. 540, pp.104-108.

Dauber J., Wolters V., Microbial activity and functional diversity in the mounds of three different ant species, Soil Biology & Biochemistry, 2000, Vol. 32, pp. 93-99.

De Groot R.S., Alkemade R., Braat L., Hein L., Willemen L., Challenges in integrating the concept of ecosystem services and values in landscape planning, management and decision making, Ecological complexity, 2010, Vol. 7, No 3, pp. 260-272.

Demakov Yu.P., Diagnostika ustojchivosti lesnyh ekosistem: metodologicheskie i metodicheskie aspekty (Diagnostics of sustainability of forest ecosystems: methodological and methodical aspects), Yoshkar-Ola, 2000, 416 p.

Dezhkin V.V., D’yakov Yu.V., Safonov V.G., Bobr (Beaver), Мoscow: Agropromizdat, 1986, 256 p.

Dinesman L.G., Vliyanie dikih mlekopitayushchih na formirovanie drevostoev (The influence of wild mammals on the formation of forest stands), Moscow: AN SSSR, 1961, 165 p.

Dixon R.A., Paiva N.L., Stress-lnduced Phenylpropanoid Metabolism, The Plant Cell, 1995, Vol. 7, pp. 1085-1097.

Dmitrienko V.K., Lyudvig N.L., Vliyanie severnogo lesnogo murav’ya (Formica aquilonia Yarrov.) na vidovoj sostav i razvitie rastenij vozle muravejnika (Influence of the northern forest ant (Formica aquilonia Yarrov.) on the species composition and development of plants near the anthill), Materialy 12 Vserossijskogo mirmekologicheskogo simpoziuma (Materials of the 12^th All-Russian Mirmecological Symposium), Novosibirsk, 2005, pp. 219-222.

Donlan J.C., Berger J., Bock C.E., Bock J.H., Burney D.A., Estes J.A., … & Soule M.E., Pleistocene rewilding: an optimistic agenda for twenty-first century conservation, The American Naturalist, 2006, Vol. 168, No 5, pp. 660-681.

Drake H.L., Horn M.A., Earthworms as a transient heaven for terrestrial denitrifying microbes: a review, Engineering in Life Sciences, 2006, Vol. 6, No 3, pp. 261-265.

Dylis N.V., Struktura lesnogo biogeocenoza (The structure of the forest biogeocenosis) Komarovskie chteniya, Moscow: Nauka, 1969, Vol. 21, 28 p.

Dymina G.D., Luga Dal’nego Vostoka (Zejsko-Bureinskoe Priamur’e) (Meadows of the Far East (Zeisko-Bureinskoe Priamurye)), Novosibirsk: Nauka, 1985, 193 p.

Dzhennings S., Nussbaum P., Dzhadd H., Evans T., Lesa vysokoj prirodoohrannoj cennosti: prakticheskoe rukovodstvo (High Conservation Value Forests: A Practical Guide), Moscow, 2005, p. 48.

Eisenhauer N., Schielzeth Н., Barnes A., Barry K., Bonn A., & Ferlian O., A multi- trophic perspective on biodiversity–ecosystem functioning research, Advances in Ecological Research, 2019, Vol. 61, pp. 1-54.

El-Komy M.H., Saleh A.A., Eranthodi A., Molan Y.Y., Characterization of novel Trichoderma asperellum isolates to select effective biocontrol agents against tomato Fusarium wilt, The Plant Pathology Journal, 2015, Vol. 31, pp. 50-60.

Ernst G., Henseler I., Felten D., Emmerling C., Decomposition and mineralization of energy crop residues governed by earthworms, Soil Biology and Biochemistry, 2009, Vol. 41, No 7, pp. 1548-1554.

EUFORGEN – European Forest Genetic Resources Programme, URL.: http://www.euforgen.org (December 14, 2020).

European Russian forests: Their current state and features of their history. O.V. Smirnova, M.V. Bobrovsky, L.G. Khanina (Eds.), Plant and Vegetation, Vol. 15, Springer, Dordrecht, 2017, 566 p.

Evstigneev O.I., Belyakov K.V., Vliyanie deyatel’nosti bobra na dinamiku rastitel’nosti malyh rek (na primere zapovednika “Bryanskij les”) (Influence of beaver activity on the dynamics of vegetation of small rivers (on the example of the “Bryansky forest”)) Byulleten’ MOIP. Otdel biologicheskij, 1997, Vol. 102, Issue 6, pp. 34-41.

Evstigneev O.I., Korotkov V.N., Braslavskaya T.Yu., Kaban i ciklicheskie mikrosukcessii v travyanom pokrove shirokolistvennyh lesov (Wild boar and cyclic micro-successions in the grass cover of broad-leaved forests), In: Biogeocenoticheskij pokrov Nerusso-Desnyanskogo poles’ya: mekhanizmy podderzhaniya biologiches-kogo raznoobraziya (Biogeocenotic cover of the Nerusso-Desnyanskogo polesia: mechanisms for maintaining biological diversity), Bryansk: Zapovednik “Bryanskij les”, 1999, pp.131-142.

Evstigneev O.I., Rubashko G.E., Chernyj sadovyj muravej i ciklicheskie sukcessii v travyanom pokrove vnutrilesnyh polyan (Black garden ant and cyclic successions in the grass cover of in-forest glades), In: Biogeocenoticheskij pokrov Nerusso-Desnyanskogo poles’ya: mekhanizmy podderzhaniya biologicheskogo raznoob-raziya (Biogeocenotic cover of the Nerusso-Desnyanskogo polesia: mechanisms for maintaining biological diversity), Bryansk: Zapovednik “Bryanskij les”, 1999, pp. 143-161.

Evstigneev O.I., Solonina O.V., Zubr i podderzhanie bioraznoobraziya lugov (na primere zapovednika Bryanskij les) (European bison and maintenance of biodiversity of meadows (on the example of nature reserve Bryansky forest)), Byulleten’ MOIP. Otdel biologicheskij, 2016, Vol. 121, Issue 2, pp. 59-65.

Evstigneev O.I., Voevodin Evstigneev O.I., Korotkov V.N., Murashev I.A., Voevodin P.V., Zoochory and peculiarities of forest community formation: a review, Russian Journal of Ecosystem Ecology, 2017, Vol. 2, No 1, pp. 1-16.

Evstigneev O.I., Solonina O.V., Phytocoenotic portrait of the European Badger, Russian Journal of Ecosystem Ecology, 2020, Vol. 5, No 1, pp. 1-26.

Evstigneev O.I., Voevodin P.V., Korotkov V.N., Murashev I.A., Zoohoriya i dal’nost’ raznosa semyan v hvojno-shirokolistvennyh lesah Vostochnoj Evropy (Zoochory and distance of seeds dissemination in coniferous-broad-leaved forests of Eastern Europe), Uspekhi sovremennoj biologii, 2013, Vol. 133, No 4, pp. 392-400.

Ferlian O., Eisenhauer N., Aguirrebengoa M., Camara M., Ramirez‐Rojas I., Santos F., … & Thakur M.P., Invasive earthworms erode soil biodiversity: A meta‐analysis, Journal of Animal Ecology, 2018, Vol. 87, No 1, pp. 162-172.

Feuda R.,  Bannikova A.A., Zemlemerova E.D., Febbraro M.D., Loy A. …, & Colangelo P., Tracing the evolutionary history of the mole, Talpa europaea, through mitochondrial DNA phylogeography and species distribution modelling, Biological Journal of the Linnean Society, 2015, Vol. 114, No 3, pp. 495-512.

Feurdean A., Ruprecht E., Molnar Z., Hutchinsond S.M., Hickler T., Biodiversity-rich European grasslands: Ancient, forgotten ecosystems, Biological Conservation, 2018, Vol. 228, pp. 224-232.

Filser J., Faber J.H., Tiunov A.V., Brussaard L., Frouz J., De Deyn G., … & Jimenez J.J., Soil fauna: Key to new carbon models, Soil, 2016, Vol. 2, pp. 565-582.

Finer L., Jurgensen M.F., Domisch T., Kilpeläinen J., Neuvonen S., Punttila P., … & Niemelä P., The role of wood ants (Formica rufa group) in carbon and nutrient dynamics of a boreal Norway spruce forest ecosystem, Ecosystems, 2013, Vol. 16, No 2, pp. 196-208.

Formozov A.N., Zveri, pticy i ih vzaimosvyazi so sredoj obitaniya (Mammals and birds and their interrelations with the environment), Moscow: Nauka, 1976, 309 p.

Formozov A.N., Zveri, pticy i ih vzaimosvyazi so sredoj obitaniya (Mammals and birds and their interrelations with the environment), Moscow: LKI, 2010, 312 p.

Frąc M., Hannula S.E., Bełka M., Jędryczka M., Fungal biodiversity and their role in soil health, Frontiers in Microbiology, 2018, Vol. 9, p. 707.

Framstad E., Biodiversity, Carbon Storage and Dynamics of Old Northern Forests, Copenhagen: Nordic Council of Ministers, 2013, 130 p.

Frelich L.E., Blossey B., Cameron E.K., Davalos A., Eisenhauer N., Fahey T., … & Maerz J.C., Side‐swiped: ecological cascades emanating from earthworm invasions, Frontiers in Ecology and the Environment, 2019, Vol. 17, No 9, pp. 502-510.

Freschet G.T., Cornwell W.K., Wardle D.A., Elumeeva T.G., Liu W., Jackson B.G., Onipchenko V.G., Soudzilovskaia N.A., Tao J., Cornelissen J.H.C. Linking litter decomposition of above- and below-ground organs to plant–soil feedbacks worldwide, Journal of Ecology, 2013, Vol. 101, pp. 943-952.

Freschet G.T., Roumet C., Comas L.H., Weemstra M., Bengough A.G., Rewald B., … & Lukac M., Root traits as drivers of plant and ecosystem functioning: current understanding, pitfalls and future research needs, New Phytologist, 2020, in press.

Fridland V.M., Problemy geografii genezisa i klassifikacii pochv (Problems of the geography of genesis and classification of soils), Moscow: Nauka, 1986, 243 p.

Fridman V.S., Eremkin G.S., Zaharova N.Yu., Vozvratnaya urbanizaciya-poslednij shans na spasenie uyazvimyh vidov ptic Evropy? (Return urbanization – the last chance to endangered species of birds in Europe and others high-urbanised regions?), Russian Journal of Ecosystem Ecology, 2016, Vol. 1, No 4, pp. 1-58.

Frouz J., Livečkova M., Albrechtova J., Chroňakova A., Cajthaml T., Pižl V., … & Šimačkova H., Is the effect of trees on soil properties mediated by soil fauna? A case study from post-mining sites, Forest Ecology and Management, 2013, Vol. 309, pp. 87-95.

Gadd G.M., Geomycology: biogeochemical transformations of rocks, minerals, metals and radionuclides by fungi, bioweathering and bioremediation, Mycological research, 2007, Vol. 111, No 1, pp. 3-49.

Galushin V.M., Kostin A.B., Kubareva N.YU., Mechnikova S.A., Romanov M.S., Znachenie mikrofragmentov lesnoj rastitel’nosti dlya sohraneniya raznoobraziya hishchnyh ptic v agrocenozah pravoberezh’ya verhnego Dona (Importance of micro-fragments of forest vegetation for preserving the diversity of birds of prey in agrocenoses of the right bank of the upper Don), Redkie vidy ptic Nechernozyomnogo centra Rossii (Rare bird species of the Non-Black Earth Center of Russia, Proc. Conf. Title), Moscow: MPGU, 1998, pp. 174-179.

Gamfeldt L., Hillebrand H., Jonsson P.R., Multiple functions increase the importance of biodiversity for overall ecosystem functioning, Ecology, 2008, Vol. 89, No 5, pp. 1223-1231.

Gamfeldt L., Snäll T., Bagchi R., Jonsson M., Gustafsson L., Kjellander P., … & Mikusiński G., Higher levels of multiple ecosystem services are found in forests with more tree species, Nature communications, 2013, Vol. 4, No 1, pp. 1-8.

Gardi C., Jeffery S., Soil Biodiversity, Brussels: European Commission, 2009, p. 27.

Gehr B., Hofer E.J., Ryser A., Vimercati E., Vogt K., Keller L.F., Evidence for nonconsumptive effects from a large predator in an ungulate prey? Behavioral Ecology, 2018, Vol. 29, No 3, pp. 724-735.

Geraskina A.P., Problemy kolichestvennoj ocenki i ucheta faunisticheskogo raznoobraziya dozhdevyh chervej v lesnyh soobshchestvah (Problems of quantification and accounting faunal diversity of earthworms in forest communities), Russian Journal of Ecosystem Ecology, 2016, Vol. 2, No 2, pp. 1-9.

Geraskina A.P., Kiseleva L.L., Karpachev A.P., Abadonova M.N., Vliyanie reintrodukcii zubrov na kompleksy dozhdevyh chervej nacional’nogo parka “Orlovskoe Poles’e” (Bison reintroduction influence on the earthworms complexes of the national park “Orlovskoey Polesye”), Russian Journal of Ecosystem Ecology, 2018, Vol. 3, No 4, pp. 1-21.

Geraskina A.P., Restoration of earthworms community (Oligochaeta: Lumbricidae) at sand quarries (Smolensk oblast, Russia), Ecological Questions, 2019, Vol. 30, No 3, pp. 7-15.

Geraskina A.P., Smirnova O.V., Korotkov V.N., Kudrevatykh I.Yu., Productivity and content of macro- and microelements in the phytomass of ground vegetation of typical and unique taiga forests of the Northern Urals (example of spruce-fir forests of the Pechora Ilych Nature Reserve), Russian Journal of Ecosystem Ecology, 2020, Vol. 5, No 2, pp. 1-13.

Geraskina A.P., Vliyanie dozhdevyh chervej raznyh morfo-ekologicheskih grupp na akkumulyaciyu ugleroda v lesnyh pochvah (Impact of earthworms of different morpho-ecological groups on carbon accumulation in forest soils), Voprosy lesnoj nauki, 2020, Vol. 3. No 2, pp. 1-20.

Gilyarov M.S., Krivoluckij D.A., Zhizn’ v pochve (Life in soil), Мoscow: Molodaya gvardiya, 1985, 191 p.

Gilyarov M.S., Rol’ stepnyh gryzunov v proiskhozhdenii entomofauny i sornopolevoj rastitel’nosti (The role of steppe rodents in the origin of entomofauna and weed-field vegetation), Dokl. AN SSSR, 1951, Vol. 79, No 4, pp. 69-71.

Gleixner G., Soil organic matter dynamics: a biological perspective derived from the use of compound-specific isotopes studies, Ecological Research, 2013, Vol. 28, No 5, pp. 683-695.

Golichenkov M.V., Novosyolov A.L., Marfenina O.E., Dobrovol’skaya T.G., Zakalyukina Yu.V., Lapygina E.V., Zamolodchikov D.G., Mikrobiologi-cheskaya harakteristika muravejnikov Lasius niger (Microbiological characteristic of anthills of Lasius niger), Izvestiya Rossijskoj akademii nauk. Seriya biologicheskaya, 2011, No 3, pp. 334-339.

Goncharov A.A., Struktura troficheskih nish v soobshchestvah pochvennyh bespozvo-nochnyh (mezofauna) lesnyh ekosistem, Dis. kand. biol. nauk (The structure of trophic niches in the communities of soil invertebrates (mesofauna) of forest ecosystems. Candidate’s thesis), Moscow: IPEE RAN im. Severcova A.N., 2014, 177 p.

Gornov A.V., Zoogennaya i fitogennaya mozaichnost’ i floristicheskoe raznoobrazie vlazhnyh lugov Nerusso-Desnyanskogo poles’ya (Zoogenic and phytogenic patterns and floristic diversity of wet meadows in the Nerusso-Desnyanskoe polesye), Byulleten’ MOIP. Otdel biologicheskij, 2011, Vol. 116, Issue 6, p. 64-69.

Gornov A.V., Rol’ royushchih zhivotnyh v podderzhanii floristicheskogo raznoobraziya lesnyh soobshchestv (The role of burrowing animals in maintaining the floristic diversity of forest communities), In: Raznoobrazie i dinamika lesnyh ekosistem Rossii (Diversity and dynamics of forest ecosystems in Russia), Vol. 2, Moscow: Tovarishhestvo nauchnyh izdanij KMK, 2013, pp. 265-276.

Gornov A.V., Rol’ kabanov v podderzhanii populyacij nekotoryh vidov lugovyh rastenij v Nerusso-Desnyanskom poles’e (The role of wild boars in reproduction populations of some species of meadow plants in the Nerusso-Desnyanskoye Polesye) Byulleten’ Bryanskogo otdeleniya Russkogo botanicheskogo obshchestva, 2014, No 2 (4), pp. 25-30.

 Grafius D.R.,  Corstanje R.,  Siriwardena G.M.,  Plummer K.E.,   Harris J.A., A bird’s eye view: using circuit theory to study urban landscape connectivity for birds, Landscape Ecology, 2017, Vol. 32, pp. 1771-1787.

Greenfacts, URL: https://www.greenfacts. org/glossary/def/ecosystem-processes.htm (December 14, 2020).

Gusev A.A., Pitanie losya i izmenenie rastitel’nosti v lesostepnyh dubravah (Moose nutrition and changes in vegetation in forest-steppe oak forests), Byulleten’ MOIP. Otdel biologicheskij, 1983, Vol. 88, Issue 6, pp. 46-50.

Gusev A.A., Funkcional’naya rol’ dikih kopytnyh zhivotnyh v zapovednyh biogeocenozah (The functional role of wild hoofed mammals in reserved biogeocenoses), In: Rol’ krupnyh hishchnikov i kopytnyh v biocenozah zapovednikov (The role of large predators and hoofed mammals in biocenoses of reserves), Moscow, 1986, pp. 94-105.

Gustafsson L., Bauhus J., Asbeck T., Augustynczik A.L.D., Basile M., Frey J., … & Knuff A., Retention as an integrated biodiversity conservation approach for continuous-cover forestry in Europe, Ambio, 2020, Vol. 49, No 1, pp. 85-97.

Hacker A.L., Coblentz B.E., Habitat selection by mountain beavers recolonizing Oregon coast range clearcuts, The Journal of wildlife management, 1993, Vol. 57, No 4, pp. 847-853.

Hale C.M., Frelich L.E., Reich P.B., Changes in hardwood forest understory plant communities in response to European earthworm invasions, Ecology, 2006, Vol. 87, No 7, pp. 1637-1649.

Hanina L.G., Bobrovskij M.V., Smirnov V.E., Grozovskaya I.S., Romanov M.S., Lukina N.V., Isaeva L.G., Funkcional’nye gruppy vidov i mikrogruppirovki lesnogo napochvennogo pokrova dlya modelirovaniya ego dinamiki (Ground vegetation modeling through functional species groups and patches in the forest floor), Matematicheskaya biologiya i bioinformatika, 2015, No 1, pp. 15-33.

Hannula S.E., Morrien E., de Hollander M., Shifts in rhizosphere fungal community during secondary succession following abandonment from agriculture, The ISME journal, 2017, Vol. 11, No 10, pp. 2294-2304.

Hansen B.B., Henriksen S., Aanes R., Sæther B.E., Ungulate impact on vegetation in a two-level trophic system, Polar Biology, 2007, Vol. 30, No 5, pp. 549-558.

Hansson K., Impact of tree species on carbon in forest soils, Doctoral Thesis, Swedish University of Agricultural Sciences, Uppsala, 2011, 56 p.

Hättenschwiler S., Tiunov A.V., Scheu S., Biodiversity and litter decomposition in terrestrial ecosystems, Annual Review of Ecology Evolution and Systematics, 2005, Vol. 36, pp. 191-218.

Hawksworth D.L., Lücking R., Fungal diversity revisited: 2.2 to 3.8 million species, In: The fungal kingdom, J. Heitman, B.J. Howlett, P.W. Crous, E.H. Stukenbrock, T.Y. James, N.A.R. Gow (Eds.), Washington: ASM Press, 2017, pp. 79-95.

Hedwall P.O., Brunet J., Trait variations of ground flora species disentangle the effects of global change and altered land-use in Swedish forests during 20 years, Global change biology, 2016, Vol. 22, No 12, pp. 4038-4047.

Hobbie S.E., Effects of plant species on nutrient cycling, Trends in ecology & evolution, 1992, Vol. 7, pp. 336-339.

Hodasheva K.S., Eliseeva V.I., Rol’ pozvonochnyh zhivotnyh – potrebitelej vetoсhnyh kormov v krugovorote zol’nyh elementov (na primere lesostepnyh dubrov) (The role of vertebrates – consumers of branch feed in the cycle of ash elements (on the example of forest-steppe oak trees)), In: Sredoobrazuyushchaya deyatel’nost’ zhivotnyh (Environment-forming activity of animals), Moscow: MGU, 1970, pp. 52-54.

Högberg M.N., Högberg P., Extramatrical ectomycorrhizal mycelium contributes one‐third of microbial biomass and produces, together with associated roots, half the dissolved organic carbon in a forest soil, New Phytologist, 2002, Vol. 154, No 3, pp. 791-795.

Holbrook K.M., Home Range and Movement Patterns of Toucans: Implications for Seed Dispersal, Biotropica, 2011, Vol. 3, No 3, pp. 357-364.

Hölldobler B., The ant fauna of Finnish Lapland, Waldhygiene, 1960, Vol. 3, No 8, pp. 229-238.

Hölldobler B., Wilson E.O., The ants, 1990, Harvard University Press.

Holodova M.V., Belousova I.P., Potreblenie i usvoenie pitatel’nyh veshchestv i energii zubrami (Bison bonasus) (Consumption and assimilation of nutrients and energy by bison (Bison bonasus)), Zoologicheskij zhurnal, 1989, Vol. 68, Issue 12, pp. 107-117.

Hooper D.U., Chapin F.S., Ewel J.J., Hector A., Inchausti P., Lavorel S., Lawton J.H., Lodge D.M., Loreau M., Naeem S., Schmid B., Setälä H., Symstad A.J., Vandermeer J., Wardle D.A., Effects of biodiversity on ecosystem functioning: a consensus of current knowledge, Ecological Monographs, 2005, Vol. 75, No 1, pp. 3-35.

Huang W., Gonzalez G., Zou X., Earthworm abundance and functional group diversity regulate plant litter decay and soil organic carbon level: A global meta-analysis, Applied Soil Ecology, 2020, Vol. 150, pp. 1-15.

Integrating Scientific Knowledge in Mixed Forests, EuMIXFOR Final Conference. COST Action FP 1206. 5–7 October 2016, Prague, Czech Republic, 73 p.

IPCC, Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems, P.R. Shukla, J. Skea, E. Calvo Buendia, V. Masson-Delmotte, H.-O. Pörtner…, & J. Malley (Eds.), 2019, 874 p., https://www.ipcc.ch/srccl/ (December 14, 2020).

Isaev A.C., Girs G.I., Vzaimodejstvie dereva i nasekomyh-ksilofagov (Interaction between tree and xylophagous insects), Novosibirsk: Nauka, 1975, 347 p.

Isaev A.C., Kiselev V.V., Vetrova V.N., Vliyanie massovogo razmnozheniya bol’shogo chernogo hvojnogo usacha na sostoyanie lesnyh biogeocenozov (Influence of mass reproduction of the great black coniferous barbel on the state of forest biogeocenoses), Problemy ekologicheskogo monitoringa i modelirovaniya ekosistem, Leningrad: Gidrometeoizdat, 1981, Vol. 4, pp. 20-31.

Isaev A.S., Pal’nikova E.N., Suhovol’skij V.G., Tarasova O.V., Dinamika chislennosti lesnyh nasekomyh-fillofagov: modeli i prognozy (Dynamics of the number of forest phyllophagous insects: models and forecasts), Moscow: КМК, 2015, 226 p.

Isaev A.S., Sukhovolsky V.G., Tarasova O.V., Palnikova E.N., Kovalev A.V., Forest insect population dynamics, outbreaks and global warming effects, John Wiley & Sons, 2017, p. 304.

Jacob M., Viedenz K., Polle A., Thomas F.M., Leaf litter decomposition in temperate deciduous forest stands with a decreasing fraction of beech (Fagus sylvatica), Oecologia, 2010, Vol. 164, No 4, pp. 1083-1094.

Jacobsen R.M., Burner R.C., Olsen S.L., Skarpaas O., Sverdrup-Thygeson A., Near-natural forests harbor richer saproxylic beetle communities than those in intensively managed forests, Forest Ecology and Management, 2020, Vol. 466, pp. 118-124.

Jastrow J.D., Amonette J.E., Bailey V.L., Mechanisms controlling soil carbon turnover and their potential application for enhancing carbon sequestration, Climatic Change, 2007, Vol. 80. No 1-2, pp. 5-23.

Jayne B., Quigley M., Influence of arbuscular mycorrhiza on growth and reproductive response of plants under water deficit: a meta-analysis, Mycorrhiza, 2014, Vol. 24, pp. 109-119.

Jenny H., Role of the plant factor in the pedogenic functions, Ecology, 1958, Vol. 39, No 1, pp. 5-16.

Jones C.G., Lawton J.H., Shachak M., Organisms as ecosystem engineers, In: Ecosystem management, F.B. Samson, F.L. Knopf (Eds.), New York: Springer, 1994, pp. 130-147.

Jones C.G., Lawton J.H., Shachak M., Positive and negative effects of organisms as physical ecosystem engineers, Ecology, 1997, Vol. 78, No 7, pp. 1946-1957.

Jurgensen M.F., Finer L., Domisch T., Kilpeläinen J., Punttila P., Ohashi M., … & Risch A.C., Organic mound‐building ants: their impact on soil properties in temperate and boreal forests, Journal of Applied Entomology, 2008, Vol. 132, No 4, pp. 266-275.

Kalyakin V.N., Turubanova S.A., Izmenenie vidovogo sostava i rasprostraneniya klyuchevyh vidov (edifikatorov) mamontovogo kompleksa Vostochnoj Evropy s pozdnego plejstocena do pozdnego golocena (Changes in the species composition and distribution of key species (edificators) of the mammoth complex of Eastern Europe from the late pleistocene to the late holocene), In: Vostochnoevropejskie lesa: istoriya v golocene i sovremennost’ (Eastern European forests: history in Holocene and contemporaneity), Moscow: Nauka, 2004, Vol. 1, pp. 96-117.

Karpachevskij L.O., Pestrota pochvennogo pokrova v lesnom biogeocenoze (Heterogeneity of soil cover in forest biogeocenosis), Moscow: Izd-vo Mosk. un-ta, 1977, 312 p.

Karpachevskij L.O., Dmitriev E.A., Skvorcova E.A., Basevich V.F., Rol’ vyvalov v formirovanii struktury pochvennogo pokrova (The role of treefalls in the formation of the soil cover structure), Struktura pochvennogo pokrova i ispol’zovanie pochvennyh resursov, Moscow: Nauka, 1978, pp. 37-42.

Karpachevskij M., Aksenov D., Esipova E., Vladimirova N., Danilova I., Kobyakov K., Zhuravleva I., Malonarushennye lesnye territorii Rossii: sovremennoe sostoyanie i utraty za poslednie 13 let (Intact forest areas of Russia: current state and losses over the past 13 years) Ustojchivoe lesopol’zovanie, 2015, Vol. 42, No 2, pp. 2-7.

Karpechko Yu.V., Gidrologicheskaya ocenka antropogennogo vozdejstviya na vodosbory v taezhnoj zone Evropejskogo Severa Rossii, Dis. dokt. geogr. nauk (Hydrological assessment of anthropogenic impact on catchments in the taiga zone of the European North of Russia. Doktor’s thesis), Saint Petersburg, 2004, 303 p.

Karpechko Yu.V., Kondrat’ev S.A., Rodionov V.Z., Shmakova M.V., Osobennosti formirovaniya ispareniya v razlichnyh po vozrastu, usloviyam proizrastaniya i produktivnosti lesah (Evaporation patterns in forests of different ages, site conditions and productivity levels), Gidrometeorologiya i ekologiya, 2020, No 58, pp. 49-67.

Kazimirov N.I., Morozova R.M., Biologicheskij krugovorot veshchestv v el’nikah Karelii (Biological circulation of substances in the spruce forests of Karelia), Leningrad: Nauka, 1973, 175 p.

Kazimirov N.I., Volkov A.D., Zyabchenko S.S., Ivanchikov A.A., Morozova R.M., Obmen veshchestv i energii v sosnovyh lesah Evropejskogo Severa (Exchange of matters and energy in pine forests of the European North), Leningrad: Nauka, 1977, 304 p.

Kaz’min V.D., Smirnov K.A., Zimnee pitanie, kormovye resursy i troficheskoe vozdejstvie zubrov na lesnye fitocenozy Central’nogo Kavkaza (Winter food, forage resources and trophic impact of bison on forest phytocenoses of the Central Caucasus), Byulleten’ MOIP. Otdel biologicheskij, 1992, Vol. 97, No 2, pp. 26-35.

Khanina L.G., Bobrovsky M.V., Komarov A.S., Mikhajlov A.V., Modeling dynamics of forest ground vegetation diversity under different forest management regimes, Forest Ecology & Management, 2007, Vol. 248, pp. 80-94.

Khlifa R., Paquette A., Messier C., Reich P.B., Munson A.D., Do temperate tree species diversity and identity influence soil microbial community function and composition?  Ecology and evolution, 2017, Vol. 7, No 19, pp. 7965-7974. 

Khlifa R., Angers D.A., Munson A.D., Understory Species Identity Rather than Species Richness Influences Fine Root Decomposition in a Temperate Plantation, Forests, 2020, Vol. 11, No 10, pp. 1091.  

Komarov A.S., Chertov O.G., Zudin S.L., Nadporozhskaya M.A., Mikhailov A.V., Bykhovets S.S., Zudina E.V., Zoubkova E.V., EFIMOD 2 — A model of growth and elements cycling of boreal forest ecosystems, Ecological Modelling, 2003, Vol. 170, pp. 373-392.

Komarov A., Chertov O., Bykhovets S., Shaw C., Nadporozhskaya M., Frolov P., … & Zubkova E., Romul_Hum model of soil organic matter formation coupled with soil biota activity. I. Problem formulation, model description, and testing, Ecological Modelling, 2017, Vol. 345, pp. 113-124. 

Koncepciya nauchno-tekhnologicheskoj programmy Soyuznogo gosudarstva «Ocenka i puti predotvrashcheniya riskov vozniknoveniya krizisnyh situacij v lesah pri intensifikacii lesnogo hozyajstva» (The concept of the scientific and technological program of the Union State «Assessment and ways of preventing the risks of crisis situations in forests during the intensification of forestry»), 2019, available at: www.cepl.rssi.ru (2020, 14 December).

Kondrat’ev S.A., Karpechko Yu.V., Shmakova M.V., Vliyanie vyrubok lesa na stok i vynos biogennyh elementov s lesnyh vodosborov Karelii (po dannym matematicheskogo modelirovaniya) (Impact of forest cutting down on runoff and nutrient removal from forest catchments of Karelia (according to mathematical modeling)), Gidrometeorologiya i ekologiya, 2020, No 59, pp. 51-66.

Korochkina L.N., Drevesnaya rastitel’nost’ v pitanii zubrov Belovezhskoj Pushchi (Woody vegetation in the diet of bison of Belovezhskaya Pushcha), Belovezhskaya Pushcha. Minsk, 1969a, pp. 120-126.

Korochkina L.N., Rajon obitaniya i stacial’noe razmeshchenie zubrov v Belovezhskoj pushche (Habitat and stationary distribution of bison in Belovezhskaya Pushcha), Belovezhskaya pushcha. Issledovaniya, Minsk: Uradzhaj, 1973, Issue 7, pp. 148-165.

Korochkina L.N., Vidovoj sostav lesnoj travyanistoj rastitel’nosti v pitanii zubrov Belovezhskoj Pushchi (Species composition of forest herbaceous vegetation in the diet of bison in Belovezhskaya Pushcha), Belovezhskaya Pushcha, Minsk, 1969b, pp. 204-221.

Korotkov V.N., Vosstanovlenie prirodnyh raznovozrastnyh lesov (Restoration of natural forests of different ages) Sovremennye koncepcii ekologii biosistem i ih rol’ v reshenii problem sohraneniya prirody i prirodopol’zovaniya, 2016, pp. 373-376.

Korotkov V.N., Osnovnye koncepcii i metody vosstanovleniya prirodnyh lesov Vostochnoj Evropy (Basic concepts and methods of restoration of natural forests in Eastern Europe), Russian Journal of Ecosystem Ecology, 2017, Vol. 2, No 1, DOI:10.21685/2500-0578-2017-1-1.

Kovalev I.V., Kovaleva N.O., Pul ligninovyh fenolov v pochvah lesnyh ekosistem (Pool of lignin phenols in soils of forest ecosystems), Lesovedenie, 2016, No 2, pp. 148-160.

Kovaleva N.O., Kovalev I.V., Ligninovye fenoly v pochvah kak biomarkery paleorastitel’nosti (Lignin phenols in soils as biomarkers of paleovegetation), Pochvovedenie, 2015, No 9, pp. 1073-1086.

Kozlo P.G., Stavrovskaya L.A., Vliyanie royushchej deyatel’nosti kabana (Sus scrofa L.) na travyanuyu rastitel’nost’ (Influence of burrowing activity of wild boar (Sus scrofa L.) on herbaceous vegetation), Zapovedniki Belorussii, Minsk, 1974, Issue 3, pp. 91-99.

Kozlovskaya L.S., Belous A.P., Izmenenie organicheskoj chasti rastitel’nyh ostatkov pod vliyaniem oligohet (Change of organic matter of plants rests under the influence of Oligochaetes), In: Vzaimootnosheniya lesa i bolota (The relationships between forest and swamp), Moscow: Nauka, 1967, pp. 43-55.

KPNI-2017: Kompleksnyj plan nauchnyh issledovanij «Ekologicheskie i social’no-ekonomicheskie ugrozy degradacii lesov Rossii v usloviyah global’nyh izmenenij i puti ih predotvrashcheniya» (Comprehensive research plan «Environmental and socio-economic threats to forest degradation in Russia in the context of global changes and ways to prevent them») available at: www.cepl.rssi.ru (2020, 14 December).

Kraus D., Krumm F., (Eds.) Integrative approaches as an opportunity for the conservation of forest biodiversity, Germany: European Forest Institute, 2013, 284 p.

Kudeyarov V.N., Zavarzin G.A., Blagodatskij S.A., Borisov A.V., Voronin P.YU. … & Chertov O.G., Puly i potoki ugleroda v nazemnyh ekosistemah Rossii (Pools and fluxes of carbon in terrestrial ecosystems in Russia), Moscow: Nauka, 2007, 315 p.

Kuijper D.P.J., Sahlén E., Elmhagen B., Chamaillé-Jammes S., Sand H., Lone K., Cromsigt, J.P.G.M., Paws without claws? Ecological effects of large carnivores in anthropogenic landscapes. Proceedings, Biological Sciences, 2016, Vol. 283, Article: 1841.

Kurakov A.V., Kharin S.A., Byzov B.A., Changes in the composition and physiological and biochemical properties of fungi during passage through the digestive tract of earthworms, Biological Bulletin, 2016, Vol. 43, pp. 290-299.

Kurcheva G.F., Rol’ pochvennyh zhivotnyh v razlozhenii i gumifikacii rastitel’nyh ostatkov (The role of soil animals in the decomposition and humification of plant residues), Moscow: Nauka, 1971, 156 p.

Kurek P., Kapusta P., Holeksa J., Burrowing by badgers (Meles meles) and foxes (Vulpes vulpes) changes soil conditions and vegetation in a European temperate forest, Ecological Research, 2014, Vol. 29, No 1, pp. 1-11.

Kurek P., Topsoil mixing or fertilization? Forest flora changes in the vicinity of badgers’ (Meles meles L.) setts and latrines, Plant and Soil, 2019, Vol. 437, pp. 1-2, pp. 327-340.

Kurkin K.A., Sistemnye issledovaniya dinamiki lugov (System studies of meadow dynamics), Moscow: Nauka, 1976, 284 p.

Kurz W.A., Dymond C.C., White T.M., Stinson G., Shaw C.H., Rampley G.J., Smyth C., Simpson B.N., Neilson E.T., Trofymow J.A., Metsaranta J., Apps M.J., CBM-CFS3: A model of carbon-dynamics in forestry and land-use change implementing IPCC standards, Ecological Modelling, 2009, Vol. 220, pp. 480-504.

Kutovaya O.V., Vliyanie dozhdevyh chervej (Oligochaeta, Lumbricidae) na biotu i organicheskoe veshchestvo dernovo-podzolistyh pochv pri raznyh sistemah zemlepol’zovaniya, Avtoref. dis kand. s-h. nauk (Influence of earthworms (Oligochaeta, Lumbricidae) on biota and organic matter of sod-podzolic soils under different land use system, Extended abstract of Candidate’s thesis), Moscow, 2012, 27 p.

Kuuluvainen T., Gap disturbance, ground microtopography, and the regeneration dynamics of boreal coniferous forests in Finland: a review, Annales Zoologici Fennici, Finnish Zoological Publishing Board, formed by the Finnish Academy of Sciences, Societas Biologica Fennica Vanamo, Societas pro Fauna et Flora Fennica, and Societas Scientiarum Fennica, 1994, pp. 35-51.

Kuz’mina E.V., Ol’chev A.V., Rozinkina I.A., Rivin G.S., Nikitin M.A., Primenenie klimaticheskoj versii modeli cosmo dlya ocenki vliyaniya izmeneniya lesistosti central’nyh rajonov Evropejskoj territorii Rossii na regional’nye meteorologicheskie usloviya (Application of the climatic version of the cosmo model to assess the impact of changes in forest cover in the central regions of the European territory of Russia on regional meteorological conditions) Meteorologiya i gidrologiya, 2017, No 9, pp. 48-58. 

 Lacey  E.A., James L.P., Cameron G.N., (Eds). Life Underground, The biology of subterrainean rodents, The University of Chicago Press Book, 2000, 479 p.

Lachat T., Wermelinger B., Gossner M., Bussler H., Isacsson G., Müller J., Saproxylic beetles as indicator species for dead-wood amount and temperature in European beech forests, Ecological Indicators, 2012, Vol. 23, pp. 323-331.

Laganiere J., Paré D., Bergeron Y., Chen H.Y., Brassard B.W., Cavard X., Stability of soil carbon stocks varies with forest composition in the Canadian boreal biome, Ecosystems, 2013, Vol. 16, pp. 852-865.

Laine K.J., Niemelä P., The influence of ants on the survival of mountain birches during an Oporinia autumnata (Lep. Geometridae) outbreak, Oecologia, 1980, Vol. 47, No 1, pp. 39-42.

Lang S.I., Cornelissen J.H.C., Klahn T., van Logtestijn R.S.P., Broekman R., Schweikert W., Aerts R., An experimental comparison of chemical traits and litter decomposition rates in a diverse range of subarctic bryophyte, lichen and vascular plant species, Journal of Ecology, 2009, Vol. 97, No 5, pp. 886-900.

Le Bayon R.C., Bullinger-Weber G., Schomburg A., Turberg P., Schlaepfer R., Guenat C., Earthworms as ecosystem engineers: a review In: Earthworms: Types, Roles and Research, C.G. Horton (Ed.). New York: Nova Science Publishers, 2017, pp. 129-178.

Lee K.E., Earthworms. Their ecology and relationships with soils and land use, Academic press (Harcourt Brace Jovanovich, Publishers), 1985, pp. 211-221.

Lee S.-G., Kim C., Kuprin A.V., Kang J.-H., Lee B.-W., Oh S.H., Lim J., Survey research on the habitation and biological information of Callipogon relictus Semenov in Gwangneung forest, Korea and Ussurisky nature reserve, Russia (Coleoptera, Cerambycidae, Prioninae), ZooKeys, 2018, No 792, pp. 45-68.

Lee S.Y., Foster R.C., Soil fauna and soil structure, Australian Journal of Soil Research, 1991, Vol. 29, pp. 745-775.       

Levina R.E., Sposoby rasprostraneniya plodov i semyan (Distribution of fruits and seeds), Moscow, 1957, 360 p.

Liang J., Crowther T.W., Picard N., Wiser S., Zhou M., Alberti G., … & De-Miguel S., Positive biodiversity-productivity relationship predominant in global forests, Science, 2016, Vol. 354, No 6309, pp. 1-15.

Logofet D.O., Evstigneev O.I., Alejnikov A.A., Morozova A.O., Sukcessiya, vyzvannaya zhiznedeyatel’nost’yu bobra (Castor fiber L.): I. Uroki kalibrovki prostoj markovskoj modeli (Succession caused by beaver (Castor fiber L.) life activity: I. What is learnt from the calibration of a simple Markov model), ZHurnal obshchej biologii, 2014, Vol. 75, No 2, pp. 95-103.

Logofet D.O., Evstigneev O.I., Alejnikov A.A., Morozova A.O., Sukcessiya, vyzvannaya zhiznedeyatel’nost’yu bobra (Castor fiber L.): II. Utochnennaya markovskaya model’ (Succession caused by beaver (Castor fiber L.) life activity: II. A refined Markov model), Zhurnal obshchej biologii, 2015, Vol. 76, No 2, pp. 126-145.

Lord C.M., Wirebach K.P., Tompkins J., Bradshaw-Wilson C., Shaffer C.L., Reintroduction of the European bison (Bison bonasus) in central-eastern Europe: a case study, International Journal of Geographical Information Science, 2020, Vol. 34, No 8, pp. 1628-1647.

Louman B., Cifuentes M., Chacón M., REDD+, RFM, Development, and Carbon Markets, Forests, 2011, Vol. 2, No 1, pp. 357-372.

Lubbers I.M., Brussaard L., Otten W., Van Groenigen J.W., Earthworm‐induced N mineralization in fertilized grassland increases both N₂O emission and crop‐N uptake, European Journal of Soil Science, 2011, Vol. 62, No 1, pp. 152-161.

Lubbers I.M., Gonzalez E.L., Hummelink E.W.J., Van Groenigen J.W., Earthworms can increase nitrous oxide emissions from managed grassland: a field study, Agriculture, ecosystems & environment, 2013, Vol. 174, pp. 40-48.

Lubbers I.M., Pulleman M.M., Van Groenigen J.W., Can earthworms simultaneously enhance decomposition and stabilization of plant residue carbon? Soil Biology and Biochemistry, 2017, Vol. 105, pp. 12-24.

Lubbers I.M., Berg M.P., De Deyn G.B., van der Putten W.H., van Groenigen J.W., Soil fauna diversity increases CO₂ but suppresses N2O emissions from soil, Global change biology, 2020, Vol. 26, No 3, pp. 1886-1898.

Lugovaya D.L., Smirnova O.V., Zaprudina M.V., Aleynikov A.A., Smirnov V.E., Micromosaic structure and phytomass of ground vegetation in main types of dark conifer forests in the pechora–ilych state nature reserve, Russian Journal of Ecology, 2013, Vol. 44, No 1, pp. 3-10.

Lukina N.V., Nikonov V.V., Biogeohimicheskie cikly v lesah Severa v usloviyah aerotekhnogennogo zagryazneniya (Biogeochemical cycles in the forests of the North under conditions of airborne industrial pollution), In 2 parts, Part 1, Apatity: Izd-vo Kol’skogo nauchnogo centra RAN, 1996, 213 p. Part 2, Apatity: Izd-vo Kol’skogo nauchnogo centra RAN, 1996, 192 p.

Lukina N.V., Nikonov V.V., Pitatel’nyj rezhim lesov severnoj tajgi: prirodnye i tekhnogennye aspekty (Nutrient regime of northern taiga forests: natural and technogenic aspects), Apatity: Izd-vo Kol’skogo nauchnogo centra RAN, 1998, 316 p.

Lukina N.V., Orlova M.A., Isaeva L.G., Plodorodie lesnyh pochv kak osnova vzaimosvyazi pochva-rastitel’nost’ (Forest soil fertility: the base of relationships between soil and vegetation), Lesovedenie, 2010, No 5, pp. 45-56.

Lukina N.V., Orlova M.A., Steinnes E., Artemkina N.A., Gorbacheva T.T., Smirnov V.E., Belova E.A., Mass-loss rates from decomposition of plant residues in spruce forests near the northern tree line subject to strong air pollution, Environmental Science and Pollution Research, 2017, Vol. 24, No 24, pp. 19874-19887.

Lukina N.V., Tikhonova E.V., Orlova M.A., Bakhmet O.N., Kryshen A.M. …& Zukert N.V., Associations between forest vegetation and the fertility of soil organic horizons in northwestern Russia, Forest ecosystems, 2019, Vol. 6, No 1, p. 34.

Lukina N., Kuznetsova A., Tikhonova E., Smirnov V., Danilova M., Gornov A., Bakhmet O., Kryshen A., Tebenkova D., Shashkov M., Knyazeva S., Linking Forest Vegetation and Soil Carbon Stock in Northwestern Russia, Forests, 2020, Vol. 11, No 9, p. 979.

Maccarthy J.W. Gap dynamics of forest trees: A review with particular attention to boreal forests, Environmental Reviews, 2001, Vol. 9, No 1, pp. 1-59.

Maes S.L., Perring M.P., Depauw L., Bernhardt-Römermann M., Blondeel H., … & Verheyen K., Plant functional trait response to environmental drivers across European temperate forest understorey communities, Plant Biology, 2020, Vol. 22, No 3, pp. 410-424.

Maestre F.T., Quero J.L., Gotelli N.J., Escudero A., Ochoa V., Delgado-Baquerizo M., García-Palacios P., Plant species richness and ecosystem multifunctionality in global drylands, Science, 2012, Vol. 335, No 6065, pp. 214-218.

Makarov M.I., Buzin I.S., Tiunov A.V., Malysheva T.I., Kadulin M.S., Koroleva N.E., Nitrogen isotopes in soils and plants of tundra ecosystems in the Khibiny Mountains, Eurasian Soil Science, 2019, Vol. 52, No 10, pp. 1195-1206.

Makeschin F., Earthworms (Lumbricidae: Oligochaeta): Important promoters of soil development and soil fertility, In: Fauna in soil ecosystems. Recycling processes, nutrient fluxes and agricultural production, G. Benckiser (Ed.), 1997, pp. 173-223.

Makkonen M., Berg M.P., Handa I.T., Hättenschwiler S., van Ruijven J., van Bodegom P.M., Aerts R., Highly consistent effects of plant litter identity and functional traits on decomposition across a latitudinal gradient, Ecology Letters, 2012, Vol. 15, pp. 1033-1041.

Mamkin V., Kurbatova J., Avilov V., Ivanov D., Kuricheva O., Varlagin A., Yaseneva I., Olchev A. Energy and CO₂ exchange in an undisturbed spruce forest and clear-cut in the Southern Taiga, Agricultural and Forest Meteorology, 2019, Vol. 265, pp. 252-268.

Manakov K.N., Nikonov V.V., Biologicheskij krugovorot mineral’nyh elementov i pochvoobrazovanie v el’nikah Krajnego Severa (Biological cycle of mineral elements and pedogenesis in the spruce forests of the Far North), Leningrad: Nauka, 1981, 196 p.

Manning P., Plas F., Soliveres S., Allan E., Maestre F.T., Mace G., Fischer M., Redefining ecosystem multifunctionality, Nature ecology & evolution, 2018, Vol. 3, p. 427.

McDaniel J.P., Stromberger M.E., Barbarick K.A., Cranshaw W., Survival of Aporrectodea caliginosa and its effects on nutrient availability in biosolids amended soil, Applied soil ecology, 2013, Vol. 71, pp. 1-6.

Metodicheskie rekomendacii po vosproizvodstvu raznovozrastnyh shirokolistvennyh lesov evropejskoj chasti SSSR (na osnove populyacionnogo analiza) (Methodological recommendations for the reproduction of broad-leaved forests of different ages in the European part of the USSR (based on population analysis), O.V. Smirnova, R.V. Popadyuk, A.A. Chistyakova et al. (Eds.), Мoscow: VASKHNIL, 1989, 19 p.

Migge-Kleian S., McLean M.A., Maerz J.C., Heneghan L., The influence of invasive earthworms on indigenous fauna in ecosystems previously uninhabited by earthworms, Biological Invasions, 2006, Vol. 8, No 6, pp. 1275-1285.

Millennium Ecosystem Assessment. Ecosystems and Human Wellbeing: Synthesis. Washington, DC: Island Press, 2005, (URL: http://www.millenniumassessment.org/en/Reports.aspx#) (December 13, 2020).

Mirkin B.M., Naumova L.G., Metod klassifikacii rastitel’nosti po Braun-Blanke v Rossii (Braun-Blanquet method of vegetation classification in Russia), Zhurnal obshchej biologii, 2009, Vol. 70, No 1, pp. 66-77.

Mlekopitayushchie v nazemnyh ekosistemah (Mammals in terrestrial ecosystems), Moscow: Nauka, 1985, 289 p.

Moradi J., Vicentini F., Šimačková H., Pižl V., Tajovský K., Stary J., Frouz J., An investigation into the long-term effect of soil transplant in bare spoil heaps on survival and migration of soil meso and macrofauna, Ecological Engineering, 2018, Vol. 110, pp. 158-164.

Mori A.S., Isbell F., Fujii S., Makoto K., Matsuoka S., Osono T., Low multifunctional redundancy of soil fungal diversity at multiple scales, Ecology letters, 2016, Vol. 19, pp. 249-259.

Mori A.S., Lertzman K.P., Gustafsson L., Biodiversity and ecosystem services in forest ecosystems: a research agenda for applied forest ecology, Journal of Applied Ecology, 2017, Vol. 54, No 1, pp. 12-27.

Mouillot D., Villéger S., Scherer-Lorenzen M., Mason N.W., Functional structure of biological communities predicts ecosystem multifunctionality, PloS one, 2011, Vol. 6, No 3, p. e17476.

Mueller K.E., Eissenstat D.M., Hobbie S.E., Oleksyn J., Jagodzinski A.M., Reich P.B., Chawick O.A., Chorover J., Tree species effects on coupled cycles of carbon, nitrogen and acidity in mineral soils at a common garden experiment, Biogeochemistry, 2015, Vol. 111, No 1-3, pp. 601-614.

Muller R.N., Nutrient relations of the herbaceous layer in deciduous forest ecosystems, In: The Herbaceous Layer in Forests of Eastern North America, F.S. Gilliam, M.R. Roberts (Eds.), New York: Oxford University Press, 2003, pp. 15-37.

Muscolo A., Bagnato S., Sidari M., Mercurio R., A review of the roles of forest canopy gaps, Journal of Forestry Research, 2014, Vol. 25, No 4, pp. 725-736.

Naeem S., Loreau M., Inchausti P., Biodiversity and ecosystem functioning: the emergence of a synthetic ecological framework, Biodiversity and ecosystem functioning: synthesis and perspectives, 2002, pp. 3-11.

Nakonechnyj N.V., Ekologicheskoe znachenie hodov obyknovennogo krota (Talpa europaea L., 1758) v formirovanii faunisticheskih kompleksov v lesnoj zone Zapadnoj Sibiri, Dis. kand. biol. nauk (The ecological significance of the passages of the common mole (Talpa europaea L., 1758) in the formation of faunal complexes in the forest zone of Western Sibiria. Candidate’s thesis), Surgut: SurGU, 2013, 176 p.

Ndiade-Bourobou D., Hardy O.J., Favreau B., Moussavou H., Nzengue E., Mignot A., Bouvet J.M., Long-distance seed and pollen dispersal inferred from spatial genetic structure in the very low-density rainforest tree, Baillonella toxisperma Pierre, in Central Africa, Molecular Ecology, 2010, Vol. 19, No 22, pp. 4949-4962.

Nebert L.D., Bloem J., Lubbers I.M., van Groenigen J.W., Association of earthworm-denitrifier interactions with increased emission of nitrous oxide from soil mesocosms amended with crop residue, Applied and Environmental Microbiology, 2011, Vol. 77, No 12, pp. 4097-4104.

Nemcev A.S., Rautian G.S., Puzachenko A.YU., Sipko T.P., Kalabushkin B.A., Mironenko I.V., Zubr na Kavkaze (Bison in the Caucasus), Majkop: Kachestvo, 2003, 292 p.

Nichols E., Spector S., Louzada J., Larsen T., Amezquita S., Favila M.E., Network T.S.R., Ecological functions and ecosystem services provided by Scarabaeinae dung beetles, Biological conservation, 2008, Vol. 141, No 6, pp. 1461-1474.

Niklasson M., Granström A., Numbers and sizes of fires: long-term spatially explicit fire history in a Swedish boreal landscape, Ecology, 2000, Vol. 81, pp. 1484-1499.

Nikonov V.V., Lukina N.V., Biogeohimicheskie funkcii lesov na severnom predele rasprostraneniya (Biogeochemical functions of forests at the northern limit of distribution), Apatity: Izd-vo Kol’skogo nauchnogo centra RAN, 1994, 315 p.

Novara A., Rühl J., La Mantia, T., Gristina L., La Bella, S., Tuttolomondo T., Litter contribution to soil organic carbon in the processes of agriculture abandon, Solid Earth, 2015, Vol. 6, No 2, pp. 425-432.

Nummi P., Kattainen S., Ulander P., Hahtola A., Bats benefit from beavers: a facilitative link between aquatic and terrestrial food webs, Biodiversity and Conservation, 2011, Vol. 20, No 4, pp. 851-859.

Nummi P., Holopainen S., Restoring wetland biodiversity using research: Whole‐community facilitation by beaver as framework, Aquatic Conservation: Marine and Freshwater Ecosystems, 2020, Vol. 30, No 9, pp. 1798-1802.

Nygaard P.H., Strand L.T., Stuanes A.O., Gap formation and dynamics after long‐term steady state in an old‐growth Picea abies stand in Norway: Above‐and belowground interactions, Ecology and evolution, 2018, Vol. 8, No 1, pp. 462-476.

O’Connor M.I., Gonzalez A., Byrnes J.E.K., Cardinale B.J., Duffy J.E., Gamfeldt L. …, & Thompson P.L., A general biodiversity-function relationship is mediated by trophic level, Oikos, 2017, Vol. 126, pp. 18-31.

Onuchin A.A., Vlagooborot gornyh lesov Sibiri: Lokal’nye i regional’nye osobennosti, Dis. dokt. bil. nauk (Moisture rotation of mountain forests of Siberia: Local and regional features. Doctor’s thesis), Krasnoyarsk, 2003, 222 p.

Orlova M.A., Lukina N.V., Kamaev I.O., Smirnov V.E., Kravchenko T.V., Mozaichnost’ lesnyh biogeocenozov i produktivnost’ pochv (Forest ecosystem mosaics and soil fertility), Lesovedenie, 2011, No 6, pp. 39-48.

Orlova M.A., Elementarnaya edinica lesnogo biogeocenoticheskogo pokrova dlya ocenki ekosistemnyh funkcij lesov (Elementary unit of the forest biogeocenotic cover for investigation of forest ecosystem functions), Trudy Karel’skogo nauchnogo centra. Seriya Ekologicheskie issledovaniya, 2013, No 6, pp. 126-132.

Orlova M., Lukina N., Tutubalina O., Smirnov V., Isaeva G., Hofgaard F., Soil nutrient’s spatial variability in forest–tundra ecotones on the Kola Peninsula, Russia, Biogeochemistry, 2013, Vol. 113, pp. 283 -305.

Orlova M.A., Lukina N.V., Smirnov V.E., Artemkina N.A., Vliyanie eli na kislotnost’ i soderzhanie elementov pitaniya v pochvah severotaezhnyh el’nikov kustarnichkovo-zelenomoshnyh (The influence of spruce on acidity and nutrient content in soils of northern taiga dwarf shrub-green moss spruce forests), Pochvovedenie, 2016, No 11, pp. 1355-1367.

Osipov A.F., Emissiya dioksida ugleroda s poverhnosti pochvy sosnyaka chernichno-sfagnovogo srednej tajgi (Carbon dioxide emission from the soil surface in a bilberry-sphagnum pine forest in the Middle Taiga), Pochvovedenie, 2013, No 5, pp. 619-626.

Osipov A.F., Emissiya dioksida ugleroda s poverhnosti pochvy spelogo sosnyaka chernichnogo v srednej tajge Respubliki Komi (Carbon dioxide emission form the soil surface in mature bilberry pine forest in Middle Taiga of the Komi Republic), Lesovedenie, 2015, No 5, pp. 356-366.

Osipov A.F., Bobkova K.S., Biologicheskaya produktivnost’ i fiksaciya ugleroda srednetaezhnymi sosnyakami pri perekhode iz srednevozrastnyh v spelye (Biological productivity and carbon sequestration of pine forests at transition from middle aged to mature in middle taiga), Lesovedenie, 2016, No 5, pp. 346-354.

Osono T., Takeda H., Accumulation and release of nitrogen and phosphorus in relation to lignin decomposition in leaf litter of 14 tree species, Ecological Research, 2004, Vol. 19, No 6, pp. 593-602.

Pahomov A.E., Bulahov V.L., Bobylev Yu.P., Harakter, velichina i masshtaby royushchej deyatel’nosti krota v dolinnyh lesah stepnoj Ukrainy (The feature, magnitude and scale of burrowing activity of a mole in the valley forests of the steppe Ukraine), In: Ohrana i racional’noe ispol’zovanie zashchitnyh lesov stepnoj zony (Protection and rational use of protective forests of the steppe zone), Dnipropetrovsk, 1987, pp. 106-114.

Pahomov A.E., Formirovanie pochvennoj mezofauny pod vozdejstviem royushchih mlekopitayushchih v bajrachnyh dubravah Prisamar’ya (Soil Mesofauna Formation Effected by Mammalia Soil Burrowers in the Ravine Oak Forests of the Samara River Area), Vestnik zoologii, 2003, Vol. 37, No 1, pp. 41-48.

Paine R.T., The Pisaster‐Tegula interaction: Prey patches, predator food preference, and intertidal community structure, Ecology, 1969, Vol. 50, No 6, pp. 950-961.

Paustian K., Lehmann J., Ogle S., Reay D., Robertson G.P., Smith P., Climate-smart soils, Nature, 2016, Vol. 532, pp. 49-57.

Perel’ T.S., Rasprostranenie i zakonomernosti raspredeleniya dozhdevyh chervej fauny SSSR (Dispersal and patterns of spreading of earthworms of the fauna of the USSR), Moscow, Nauka, 1979, 272 p.

pleistocenepark.ru (December 12, 2020).

Poeydebat C., Jactel H., Moreira X., Koricheva J., Barsoum N., Bauhu, J., … & Gravel D., Climate affects neighbour-induced changes in leaf chemical defences and tree diversity-herbivory relationships, Functional Ecology, 2020, pp. 1-15.

Pogrebnyak P.S., Osnovy lesnoj tipologii (Fundamentals of forest typology), Kiev: AN USSR, 1955, 456 p.

Pollierer M.M., Scheu S., Tiunov A.V., Isotope analyses of amino acids in fungi and fungal feeding Diptera larvae allow differentiating ectomycorrhizal and saprotrophic fungi‐based food chains, Functional Ecology, 2020, Vol. 34, No 11, pp. 2375-2388.

Polyanskaya L.M., Yumakov D.D., Tyugaj Z.N., Stepanov A.L., Sootnoshenie gribov i bakterij v temnogumusovoj lesnoj pochve (Fungi and bacteria ratio in the dark humus forest soil), Pochvovedenie, 2020, No 9, pp. 1094-1099.

Potapov A.M., Semenyuk I.I., Tiunov A.V., Seasonal and age-related changes in the stable isotope composition (15N/14N and 13C/12C) of millipedes and collembolans in a temperate forest soil, Pedobiologia, 2014, Vol. 57, No 4-6, pp. 215-222.

Potapov A.M., Tiunov A.V., Scheu S., Larsen T., Pollierer M.M., Combining bulk and amino acid stable isotope analyses to quantify trophic level and basal resources of detritivores: a case study on earthworms, Oecologia, 2019, Vol. 189, No 2, pp. 447-460.

Pretzsch H., Steckel M., Heym M., Biber P., Ammer C., Ehbrecht M., … & Vast F., Stand growth and structure of mixed-species and monospecific stands of Scots pine (Pinus sylvestris L.) and oak (Q. robur L., Quercus petraea (M att.) L iebl.) analysed along a productivity gradient through Europe, European Journal of Forest Research, 2020, Vol. 139, No 3, pp. 349-367.

Pugnaire F.I., Morillo J.A., Peñuelas J., Reich P.B., Bardgett R.D., Gaxiola A., … & Van Der Putten W.H., Climate change effects on plant-soil feedbacks and consequences for biodiversity and functioning of terrestrial ecosystems, Science advances, 2019, Vol. 5, No 11, p. eaaz1834.

Pukkala T., Instructions for optimal any-aged forestry, Forestry, An International Journal of Forest Research, 2018, Vol. 91, No 5, pp. 563-574.

Pulleman M.M., Six J., Uyl A., Marinissen J.C.Y., Jongmans A.G., Earthworms and management affect organic matterincorporation and microaggregate formation in agricultural soils, Appl. Soil Ecol., 2005, Vol. 29, pp. 1-15.

Pülzl H., Kleinschmit D., Arts B., Bioeconomy–an emerging meta-discourse affecting forest discourses? Scandinavian Journal of Forest Research, 2014, Vol. 29, No 4, pp. 386-393.

Punttila P., Kilpeläinen J., Distribution of mound-building ant species (Formica spp., Hymenoptera) in Finland: preliminary results of a national survey, Annales Zoologici Fennici, 2009, Vol. 46, No 1, pp. 1-15.

Rafes P.M., Rol’ i znachenie rastitel’noyadnyh nasekomyh v lesu (The role and significance of herbivorous insects in the forest), Moscow: Nauka, 1968, 233 p.

Ramenskij L.G., Vvedenie v kompleksnoe pochvenno-geobotanicheskoe issledovanie zemel’ (Introduction to integrated soil-geobotanical research of lands), Leningrad: Sel’hozgiz, 1938, 620 p.

Rämö J., Tahvonen O., Optimizing the harvest timing in continuous cover forestry, Environmental and Resource Economics, 2017, Vol. 67, pp. 853-868.

Rampino M.R., Shen S.Z., The end-Guadalupian (259.8 Ma) biodiversity crisis: the sixth major mass extinction? Historical Biology, 2019, pp. 1-7.

Rastitel’noyadnye zhivotnye v biogeocenozah sushi (Herbivorous animals in land biogeocenoses: Proc. All-Union Conference), Valdai, 3-6 June 1984, Moscow: Nauka, 1986, 189 p.

Reich P.B., Oleksyn J., Modrzynski J., Mrozinski P., Hobbie S.E., Eissenstat D.M., Tjoelker M.G., Linking litter calcium, earthworms and soil properties: a common garden test with 14 tree species, Ecology letters, 2005, Vol. 8, No 8, pp. 811-818.

Remezov N.P., Eshche o roli lesa v pochvoobrazovanii (More about the role of forests in pedogenesis), Pochvovedenie, 1956, No 4, pp.70-79.

Remezov N.P., O roli lesa v pochvoobrazovanii (About the role of forests in pedogenesis), Pochvovedenie, 1953, No 12, pp. 74-83.

Romanov M.S., Evstigneev O.I., Mestoobitaniya hishchnyh ptic i chernogo aista v svyazi s prostranstvennoj strukturoj lesnogo pokrova (Habitats of diurnal raptors and the black stork in relation to the spatial structure of forest cover), Russian Journal of Ecosystem Ecology, 2016, Vol. 1, No 3, pp. 1-20.

Rooney T.P., Deer impacts on forest ecosystems: a North American perspective, Forestry: An International Journal of Forest Research, 2001, Vol. 74, No 3, pp. 201-208.

Roseberry J.L., Woolf A., Habitat-population density relationships for white-tailed deer in Illinois, Wildlife Society Bulletin, 1998, pp. 252-258.

Rosenfeld E.J., Assessing the ecological significance of linkage and connectivity for avian populations in urban areas, PhD thesis, University of Birmingham, 2012, 146 p.

Rozhkov A.C., Derevo i nasekomoe (Tree and insect), Novosibirsk: Nauka, 1981, 194 p.

Rubashko G.E., Hanina L.G., Smirnov V.E., Dinamika rastitel’nosti gruppirovok muravejnikov Formica rufa (Dynamics of plant communities related to the activity of Formica rufa ants), Zoologicheskij zhurnal, 2010, Vol. 89, No 12, pp. 1448-1455.

Sablina T.B., Kopytnye Belovezhskoj Pushchi (Hoofed mammals of Belovezhskaya Pushcha), Moscow: Nauka, 1955, 192 p.

Saikkonen T., Vahtera V., Koponen S., Suominen O. Effects of reindeer grazing and recovery after cessation of grazing on the ground-dwelling spider assemblage in Finnish Lapland, PeerJ, 2019, Vol. 7, p. e7330.

Salemaa M., Derome J., Nojd P., Response of boreal forest vegetation to the fertility status of the organic layer along a climatic gradient, Boreal Environment Research, 2008, Vol. 13, pp. 48-66.

Sandor M., Schrader S., Earthworms affect mineralization of different organic amendments in a microcosm study, Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture, 2007, Vol. 63, pp. 442-447.

Sauvadet M., Chauvat M., Brunet N., Bertrand I., Can changes in litter quality drive soil fauna structure and functions? Soil Biology and Biochemistry, 2017, Vol. 107, pp. 94-103.

Scharenbroch B.C., Bockheim J.G., Impacts of forest gaps on soil properties and processes in old growth northern hardwood-hemlock forests, Plant and soil, 2007, Vol. 294, No 1-2, pp. 219-233.

Scheller R.M., Mladenoff D.J., An ecological classification of forest landscape simulation models: tools and strategies for understanding broad-scale forested ecosystems, Landscape Ecology, 2007, Vol. 22, No 4, pp. 491-505.

Scherer-Lorenzen M., The functional role of biodiversity in the context of global change In: Forests and global change, D.A. Coomes, D.F.R.P. Burslem, W.D. Simonson (Eds.), Cambridge: Cambridge University Press, 2013, pp. 195-237.

Schlick-Steiner B.C., Steiner F.M., Moder K., Seifert B., Sanetra M., Dyreson E., … & Christian E.A., multidisciplinary approach reveals cryptic diversity in Western Palearctic Tetramorium ants (Hymenoptera: Formicidae), Molecular Phylogenetics and Evolution, 2006, Vol. 40, No 1, pp. 259-273.

Schliemann S.A., Bockheim J.G., Influence of gap size on carbon and nitrogen biogeochemical cycling in Northern hardwood forests of the Upper Peninsula, Michigan, Plant and soil, 2014, Vol. 377, No 1-2, pp. 323-335.

Schliemann S.A., Bockheim J.G., Methods for studying treefall gaps: a review, Forest ecology and management, 2011, Vol. 261, No 7, pp. 1143-1151.

Schmidt M.W., Torn M.S., Abiven S., Dittmar T., Guggenberger G., Janssens I. A., … & Nannipieri P., Persistence of soil organic matter as an ecosystem property, Nature, 2011, Vol. 478, No 7367, p. 49.

Schneider A.K., Hohenbrink T.L., Reck A., Zangerlé A., Schröder B., Zehe E., van Schaik L., Variability of earthworm-induced biopores and their hydrological effectiveness in space and time, Pedobiologia, 2018, Vol. 71, pp. 8-19.

Schuldt A., Assmann T., Brezzi M., Buscot F., Eichenberg D., Gutknecht J., … & Liu X., Biodiversity across trophic levels drives multifunctionality in highly diverse forests, Nature communications, 2018, Vol. 9, No 1, p. 2989.

Seidl R., Fernandes P.M., Fonseca T.F., Gillet F., Jönsson A.M., … & Mohren F., Modelling natural disturbances in forest ecosystems: a review, Ecological Modelling, 2011, Vol. 222, No 4, pp. 903-924.

Semenov M.V., Metabarkoding i metagenomika v pochvenno-ekologicheskih issledovaniyah: uspekhi, problemy i vozmozhnosti (Metabarcoding and metagenomics in soil ecology research: achievements, challenges and opportunities), Zhurnal obshchej biologii, 2019, Vol. 80, No 6, pp. 403-417.

Shanin V.N., Komarov A.S., Mikhailov A.V., Bykhovets S.S., Modelling carbon and nitrogen dynamics in forest ecosystems of Central Russia under different climate change scenarios and forest management regimes, Ecological Modelling, 2011, Vol. 222, No 14, pp. 2262-2275.

Shanin V., Mäkipää R., Shashkov M., Ivanova N., Shestibratov K., Moskalenko S., … & Osipov A., New procedure for the simulation of belowground competition can improve the performance of forest simulation models, European Journal of Forest Research, 2015, Vol. 134, No 6, pp. 1055-1074.

Shanin V.N., Grabarnik P.Ya., Byhovec S.S., Chertov O.G., Priputina I.V., Shashkov M.P., … & Ruchinskaya E.V., Parametrizaciya modeli produkcionnogo processa dlya dominiruyushchih vidov derev’ev Evropejskoj chasti RF v zadachah modelirovaniya dinamiki lesnyh ekosistem (Parametrization of the production process model for the dominant tree species in the European part of the Russian Federation in the problems of modeling the dynamics of forest ecosystems), Mathematical Biology and Bioinformatics, 2019, Vol. 14, No 1, pp. 54-76.

Shanin V., Grabarnik P., Shashkov M., Ivanova N., Bykhovets S., FrolovP., Stamenov M., Crown asymmetry and niche segregation as an adaptation of trees to competition for light: conclusions from simulation experiments in mixed boreal stands, Mathematical and Computational Forestry and Natural-Resource Sciences, 2020, Vol. 12, No 1, pp. 26-49.

Shekhovtsov S.V., Rapoport I.B., Poluboyarova T.V., Geraskina A.P., Golovanova E.V., Peltek S.E., Morphotypes and genetic diversity of Dendrobaena schmidti (Lumbricidae, Annelida), Vavilov Journal of Genetics and Breeding, 2020, Vol. 24, No 1, pp. 48-54.

Shevchenko N.E., Rol’ Bison bonasus (Linnaeus, 1758) v formirovanii mozaiki prirodnogo lesnogo pokrova Vostochnoj Evropy. Soobshchenie pervoe. Dinamika areala i osobennosti troficheskoj i topicheskoj deyatel’nosti evropejskogo zubra v pozdnem golocene na territorii Vostochnoj Evropy (The role of Bison bonasus (Linnaeus, 1758) in the mosaic formation of natural forest cover in Eastern Europe. First article. The dynamics of the area, and features of the food and topical activity of the european bison in the Late Holocene in Eastern Europe), Russian Journal of Ecosystem Ecology, 2016, Vol. 1, No 2, pp. 1-41.

Shevchenko N.E., Kuznecova A.I., Teben’kova D.N., Smirnov V.E., Geraskina A.P., Gornov A.V., Tihonova E.V., Lukina N.V., Sukcessionnaya dinamika rastitel’nosti i zapasy pochvennogo ugleroda v hvojno-shirokolistvennyh lesah severo-zapadnogo Kavkaza (Succession dynamics of vegetation and storages of soil carbon in mixed forests of northwestern Caucasus), Lesovedenie, 2019, No 3, pp. 163-176.

Siemann E., Carrillo J.A., Gabler C.A., Zipp R., Rogers W.E., Experimental test of the impacts of feral hogs on forest dynamics and processes in the southeastern US, Forest Ecology and Management, 2009, Vol. 248, pp. 546-533.

Simmons L.W., Ridsdill-Smith T.J. (eds.), Ecology and evolution of dung beetles, Oxford: Blackwell Publishing, 2011, pp. 1-20.

Six J., Bossuyt H., Degryze S., Denef K.A., History of research on the link between (micro) aggregates, soil biota, and soil organic matter dynamics, Soil and Tillage Research, 2004, Vol. 79, No 1, pp. 7-31.

Sklyarov G.A., K voprosu o deyatel’nosti krotov v pochvah dernovo-podzolistoj zony (To the question of the activity of moles in the soils of the sod-podzolic zone), Pochvovedenie, 1953, No 8, pp. 51-57.

Skvorcova E.B., Ulanova N.G., Basevich V.F., Ekologicheskaya rol’ vetrovalov (The ecological role of windblows), Мoscow: Lesnaya promyshlennost’, 1983, 192 p.

Smirnov V.E., Funkcional’naya klassifikaciya rastenij metodami mnogomernoj statistiki (Functional classification of plants by multivariate analysis), Matematicheskaya biologiya i bioinformatika, 2007, Vol. 2, No 1, pp. 1-17.

Smirnova O.V., Struktura travyanogo pokrova shirokolistvennyh lesov (Grass cover structure of broad-leaved forests), Moscow: Nauka, 1987, 207 p.

Smirnova O.V., Populyacionnaya organizaciya biocenoticheskogo pokrova lesnyh landshaftov (Population organization of biocenotic cover of forest landscapes), Uspekhi sovremennoj biologii, 1998, Vol. 118, No 2, pp. 148-165.

Smirnova O.V., Hanina L.G., Smirnov V.E., Ekologo-cenoticheskie gruppy v rastitel’nom pokrove lesnogo poyasa Vostochnoj Evropy (Ecological-cenotic groups in the vegetation cover of forest belt of Eastern Europe), In: Vostochno-Evropejskie lesa: istoriya v golocene i sovremennost’ (Eastern European forests: history in Holocene and contemporaneity), Moscow: Nauka, 2004, Vol. 1, pp. 165-175.

Smirnova O.V., Prirodnaya organizaciya biogeocenoticheskogo pokrova lesnogo poyasa Vostochnoj Evropy. Teoreticheskie predstavleniya biogeocenologii i populyacionnoj biologii (The natural organization of biocenotic cover of forest belt of Eastern Europe. Theoretical concepts of biogeocenology and population biology), In: Vostochnoevropejskie lesa: istoriya v golocene i sovremennost’ (Eastern European forests: history in Holocene and contemporaneity), Moscow: Nauka, 2004, Vol. 1, pp. 14-25.

Smirnova O.V., Toropova N.A., Potential vegetation and potential ecosystem cover, Biology Bulletin Reviews, 2017, Vol. 7, No 2, pp. 139-149.

Smirnova O.V., Shevchenko N.E., Khanina L.G., Bobrovsky M.V., Refugium of the boreal forests of the circumpolar Urals, Biology Bulletin, 2018, Vol. 45, No 2, pp. 223-229.

Smirnova O.V., Geraskina A.P., Current northern Eurasia forest condition: methods of analysis and restoration of natural biota in protected areas. Literature review and recommendations for required research in protected areas, Russian Journal of Ecosystem Ecology, 2019, Vol. 4, No 1, pp. 1-12.

Smirnova O.V., Geraskina A.P., Korotkov V.N., Natural zonality of the forest belt of Northern Eurasia: myth or reality? Part 1 (literature review), Russian Journal of Ecosystem Ecology, 2020, Vol. 5, No 1, pp. 19-38.

Sobek S., Tscharntke T., Scherber C., Schiele S., Steffan-Dewenter I., Canopy vs. understory: Does tree diversity affect bee and wasp communities and their natural enemies across forest strata? Forest Ecology and Management, 2009, Vol. 258, No 5, pp. 609-615.

Söderbergh I., Ledermann T., Algorithms for simulating thinning and harvesting in five European individual-tree growth simulators: a review, Computers and Electronics in Agriculture, 2003, Vol. 39, No 2, pp. 115-140.

Solov’ev V.A., Biologiya i hozyajstvennoe znachenie barsukov Vyatsko-Kamskogo mezhdurech’ya, Dis. kand. biol. nauk (Biology and economic importance of badgers in the Vyatka-Kama interstream area, Candidate’s thesis,), Kirov, 2007, 162 p.

Spurgeon D.J. Keith A.M., Schmidt O., Lammertsma D.R., Faber J.H., Land-use and land-management change: relationships with earthworm and fungi communities and soil structural properties, BMC ecology, 2013, Vol. 13, No 1, p. 46.

Sredoobrazuyushchaya deyatel’nost’ zhivotnyh (Environment-forming activity of animals, Proc. Conf. Title), 17-18 December 1970, Moscow: Nauka, 1970, 101 p.

Steckel M., del Río M., Heym M., Aldea J., Bielak K., Brazaitis G., … & Jansons A., Species mixing reduces drought susceptibility of Scots pine (Pinus sylvestris L.) and oak (Quercus robur L., Quercus petraea (Matt.) Liebl.) – Site water supply and fertility modify the mixing effect, Forest Ecology and Management, 2020, Vol. 461, pp. 117908.

Storch D., Bohdalkovа E., Okie J., The more‐individuals hypothesis revisited: the role of community abundance in species richness regulation and the productivity–diversity relationship, Ecology Letters, 2018, Vol. 21, No 6, pp. 920-937.

Striganova B.R., Issledovanie roli mokric i dozhdevyh chervej v processah gumifikacii razlagayushchejsya drevesiny (Investigation of the role of woodlice and earthworms in the processes of humification of decaying wood), Pochvovedenie, 1968, No 8, pp. 85-90.

Striganova B.R., Pitanie pochvennyh saprofagov (Nutrition of soil saprophages), Moscow: Nauka, 1980, 244 p.

Striganova B.R., Struktura i funkcii soobshchestv pochvoobitayushchih zhivotnyh (Structure and functions of communities of soil inhabiting animals), In: Strukturno-funkcional’naya rol’ pochv i pochvennoj bioty v biosphere (Structural and functional role of soils and soil biota in the biosphere), Moscow: Nauka, 2003, pp. 151-173.

Sukachev V.N., Rastitel’nye soobshchestva (Plant communities), Мoscow: Kniga, 1928, 232 p.

Sukachev V.N., Terminologiya osnovnyh ponyatij fitocenologii (Terminology of the basic concepts of phytocenology), Sovremennaya botanika, 1935, Vol. 5, pp. 11-21.

Sukachev V.N., Dinamika lesnyh biogeocenozov. Osnovy lesnoj biogeocenologii (Dynamics of forest biogeocenoses. Fundamentals of forest biogeocenology), Мoscow: Nauka, 1964, pp. 458-486.

Sukachev V.N., Osnovy lesnoj tipologii i biogeocenologii. Izbrannye trudy (Fundamentals of forest typology and biogeocenology. Selected Works), Leningrad: Nauka, 1972, 418 p.

Sundqvist M.K., Wardle D.A., Olofsson E., Giesler R., Gundale M.J., Chemical properties of plant litter in response to elevation: subarctic vegetation chalenges phenolic alocation theories, Functional Ecology, 2012, Vol. 26, No 3, pp. 1090-1099.

Suominen O., Olofsson J., Impacts of semi-domesticated reindeer on structure of tundra and forest communities in Fennoscandia: a review, Annales Zoologici Fennici, 2000, Vol. 37, No 4, pp. 233-249.

Swift M.J., Human impacts on biodiversity and ecosystem services: an overview, In: The Fungal Community its Organization and Role in Ecosystems (Eds. J. Dighton, J.F. White, P. Oudemans), Boca Raton, FL: CRC Press, 2005, pp. 627-641.

Symstad A.J., Tilman D., Willson, J., Knops J.M., Species loss and ecosystem functioning: effects of species identity and community composition, Oikos, 1998, Vol. 81, pp. 389-397.

Talashilkar S.C., Bhangarath P.P., Mehta V.B., Changes in chemical properties during composting of organic residues as influenced by earthworm activity, Journal of the Indian Society of Soil Science, 1999, Vol. 47, pp. 50-53.

The afterlife of a tree, A. Bobiec (Ed.), WWF Poland, 2005, 248 p.

The Economics of Ecosystems and Biodiversity: Mainstreaming the Economics of Nature. A synthesis of the approach, conclusions and recommendations of TEEB, Malta: Progress Press, 2010, 49 p.

Tihomirova L.G., O vliyanii royushchej deyatel’nosti krota na rastitel’nost’ lugov Moskovskoj oblasti (On the influence of the burrowing activity of a mole on the vegetation of meadows in the Moscow region), In: Struktura i funkcional’no-biogeocenoticheskaya rol’ zhivotnogo naseleniya sushi. Materialy soveshchaniya MOIP. Sekciya zoologii (The structure and functional-biogeocenotic role of the animal population of the land. Materials of the MOIP meeting. Zoology Section), Moscow: Nauka, 1967, pp. 97-99.

Tiunov A.V., Kuznecova N.A., Sredoobrazuyushchaya deyatel’nost’ nornyh dozhdevyh chervej (Lumbricus terrestris L.) i prostranstvennaya organizaciya pochvennoj bioty (Environmental activity of anecic earthworms (Lumbricus terrestris L.) and spatial organization of soil communities), Izvestiya Rossijskoj akademii nauk. Seriya biologicheskaya, 2000, No 5, pp. 606-617.

Tiunov A.V., Metabioz v pochvennoj sisteme: vliyanie dozhdevyh chervej na strukturu i funkcionirovanie pochvennoj bioty, Avtoref. dis. dokt. biol. nauk (Metabiosis in soil system: impact of earthworms on the structure and functioning of soil biota, Extended abstract of Doctor’s thesis), Moscow: IPEE, 2007, 44 p.

Tobner C.M., Paquette A., Gravel D., Reich P.B., Williams L.J., Messier C., Functional identity is the main driver of diversity effects in young tree communities, Ecology letters, 2016, Vol. 19, No 6, pp. 638-647.

Tolkach V.N., Dvorak L.E., Izmenenie nadzemnoj fitomassy zhivogo napochvennogo pokrova pod vliyaniem dikih kopytnyh (Changes in the aboveground phytomass of the living ground cover under the influence of wild hoofed mammals), Belovezhskaya pushcha, 1980, Issue 4, pp. 29-38.

Toropova N.A., Rol’ geterotrofov v formirovanii mozaichno-yarusnoj struktury lesov (The role of heterotrophs in the formation of the mosaic-tiered structure of forests), In: Vostochnoevropejskie shirokolistvennye lesa (Eastern European broadleaf forests), Moscow: Nauka, 1994, pp. 228-241.

Tresch S., Frey D., Le Bayon R.C., Zanetta A., Rasche F., Fliessbach A., Moretti M., Litter decomposition driven by soil fauna, plant diversity and soil management in urban gardens, Science of the Total Environment, 2019, Vol. 658, pp. 1614-1629.

Treseder K.K., Lennon J.T., Fungal traits that drive ecosystem dynamics on land, Microbiology and Molecular Biology Reviews, 2015, Vol. 79, pp. 243-262.

Udra I.F., Rasselenie rastenij i voprosy paleo- i biogeografii (Plant dispersal and issues of paleo and biogeography), Kiev: AN USSR, 1988, 197 p.

Ulanova N.G., The effects of windthrow on forests at different spatial scales: a review, Forest ecology and management, 2000, Vol. 135, No 1-3. pp. 155-167.

Urban A.V., Prokushkin A.S., Korets M.A., Panov A.V., Gerbig C., Heimann M., Influence of the Underlying Surface on Greenhouse Gas Concentrations in the Atmosphere Over Central Siberia, Geography and Natural Resources, 2019, Vol. 40, No 3, pp. 221-229.

Van Breemen N., Finzi A.C., Plant-soil interactions: ecological aspects and evolutionary implications, Biogeochemistry, 1998, Vol. 42, pp. 1-19.

Van der Plas F., Biodiversity and ecosystem functioning in naturally assembled communities, Biological Reviews, 2019, Vol. 94, No 4, pp. 1220-1445.

Van der Plas F., Manning P., Allan E., Scherer-Lorenzen M., Verheyen K., Wirth C., … & Barbaro L. Jack-of-all-trades effects drive biodiversity–ecosystem multifunctionality relationships in European forests, Nature communications, 2016, Vol. 7, No 1, pp. 1-11.

Van der Plas F., Ratcliffe S., Ruiz‐Benito P., Scherer‐Lorenzen M., Verheyen K., Wirth C., … & Bastias C.C., Continental mapping of forest ecosystem functions reveals a high but unrealised potential for forest multifunctionality, Ecology letters, 2018, Vol. 21, No 1, pp. 31-42.

Van Groenigen J.W., Lubbers I.M., Vos H.M., Brown G.G., De Deyn G.B., Van Groenigen K.J., Earthworms increase plant production: a meta-analysis, Scientific report, 2014, Vol. 4, pp. 63-65.

Van Groenigen J.W., Van Groenigen K.J., Koopmans G.F., Stokkermans L., Vos H.M., Lubbers I.M., How fertile are earthworm casts? A meta-analysis, Geoderma, 2019, Vol. 338, pp. 525-535.

Van Klink R., van Laar-Wiersma J., Vorst O., Smit C., Rewilding with large herbivores: Positive direct and delayed effects of carrion on plant and arthropod communities, PloS one, 2020, Vol. 15, No 1, p. e0226946.

Van Meerbeek K., Muys B., Schowanek S.D., Svenning J.C., Reconciling Conflicting Paradigms of Biodiversity Conservation: Human Intervention and Rewilding, BioScience, 2019, Vol. 69, No 12, pp. 997-1007.

Vasile M., The vulnerable bison: practices and meanings of rewilding in the Romanian Carpathians, Conservation and Society, 2018, Vol. 16, No 3, pp. 217-231.

Veen G.F.C., Olff H., Interactive effects of soil-dwelling ants, ant mounds and simulated grazing on local plant community composition, Basic and Applied Ecology, 2011, Vol. 12, No 8, pp. 703-712.

Vereshchagin N.K., Rusakov O.S., Kopytnye Severo-Zapada SSSR (istoriya, obraz zhizni i hozyajstvennoe ispol’zovanie (Hoofed mammals North-West of the USSR (history, way of life and practical use)), Leningrad: Nauka, 1979, 309 p.

Verheyen K., Vanhellemont M., Auge H., Baeten L., Baraloto C., Barsoum N., … & Haase J., Contributions of a global network of tree diversity experiments to sustainable forest plantations, Ambio, 2016, Vol. 45, No 1, pp. 29-41.

Vesterdal L., Clarke N., Sigurdsson B.D., Gundersen P., Do tree species influence soil carbon stocks in temperate and boreal forests? Forest Ecology and Management, 2013, Vol. 309, pp. 4-18.

Vicente-Silva J., Bergamin R. S., Zanini K.J.,   Pillar V.D.,  Mülle S.C., Assembly patterns and functional diversity of tree species in a successional gradient of Araucaria forest in Southern Brazil, Natureza & Conservação, 2016, Vol. 14, No 2, pp. 67-73.

Vostochnoevropejskie lesa: istoriya v golocene i sovremennost’ (Eastern European forests: history in the Holocene and contemporaneity), Moscow: Nauka, 2004, Vol. 1, 479 p.

Vostochnoevropejskie shirokolistvennye lesa (Eastern European broadleaf forests), Moscow: Nauka, 1994, 364 p.

Wagg C., Bender S.F., Widmer F., Van der Heijden M.G.A., Soil biodiversity and soil community composition determine ecosystem multifunctionality, Proceedings of the National Academy of Sciences, 2014, Vol. 11, No 14, pp. 5266-5270.

Wall D., Soil ecology and ecosystem services, Oxford, UK: Oxford University Press, 2012. 424 p.

Wardle D.A., Communities and Ecosystems: Linking Aboveground and Belowground Components, New Jerse: Princeton Univ. Press, Princeton, 2002, 391 p.

Whelan C.J., Şekercioğlu Ç.H., Wenny D.G., Why birds matter: from economic ornithology to ecosystem services, Journal of Ornithology, 2015, Vol. 156, No 1, pp. 227-238.

Wikström P., Edenius L., Elfving B., Eriksson L., Lämas T., Sonesson J., Öhman K., Wallerman J., Waller C., Klintebäck F., The Heureka Forestry Decision Support System: An Overview, Mathematical & Computational Forestry & Natural Resource Sciences, 2011, Vol. 3, No 2, pp. 87-95.

Wirthner S., The role of wild boar (Sus scrofa L.) rooting in forest ecosystems in Switzerland, A dissertation for the degree of doctor in science, Zurich, 2011, 103 p.

Wright J.P., Jones C.G., Flecker A.S., An ecosystem engineer, the beaver, increases species richness and the landscape scale, Oecologia, 2002, Vol. 132, pp. 96-101.

Wright J.P., Jones C.G. The concept of organisms as ecosystem engineers ten years on: progress, limitations, and challenges, BioScience, 2006, Vol. 56, No 3, pp. 203-209.

Yamamoto S.-I., Forest Gap Dynamics and Tree Regeneration, Journal of Forest Research, 2012, Vol. 5, No 4, pp. 223-229.

Yang X., Chen J., Plant litter quality influences the contribution of soil fauna to litter decomposition in humid tropical forests, southwestern China, Soil Biology and Biochemistry, 2009, Vol. 41, No 5, pp. 910-918.

Yanickaya T., Prakticheskoe rukovodstvo po vydeleniyu lesov vysokoj prirodoohrannoj cennosti (A practical guide to identifying high conservation value forests), Vsemirnyj fond dikoj prirody (WWF), Moscow, 2008, 136 p.

Yatso K.N., Lilleskov E.A., Effects of tree leaf litter, deer fecal pellets, and soil properties on growth of an introduced earthworm (Lumbricus terrestris): implications for invasion dynamics, Soil Biology and Biochemistry, 2016, Vol. 94, pp. 181-190.

Yokoyama K., Kai H., Koga T., Kawaguchi S., Effect of dung beetle, Onthophagus lenzii H. on nitrogen transformation in cow dung and dung balls, Soil Science and Plant Nutrition, 1991, Vol. 37, No 2, pp. 341-345.

Zagidullina A., Drobyshev I., Sohranenie i imitaciya estestvennogo dinamicheskogo raznoobraziya lesnogo pokrova: obzor koncepcij i metodicheskih podhodov (Conservation and simulation of natural dynamic diversity of forest cover: an overview of concepts and methodological approaches), Ustojchivoe lesopol’zovanie, 2017, Vol. 50, No 2, pp.  22-31.

Zaharov A.A., Muravej, sem’ya, koloniya (Ant, family, colony), Moscow: Nauka, 1978, 144 p.

Zamolodchikov D.G., Korovin G.N., Utkin A.I., Chestnyh O.V., Songen B., Uglerod v lesnom fonde i sel’skohozyajstvennyh ugod’yah Rossii (Carbon in the forest fund and agricultural lands of Russia), Moscow: КМК, 2005, 212 p. 

Zaugol’nova L.B, Martynenko V.B., Opredelitel’ tipov lesa Evropejskoj Rossii (Guide on forest types in European Russia), 2012, Web-site, available at: http://www.cepl.rssi.ru/bio/forest/ (2020, 14 December).

Zaugol’nova L.B., Morozova O.V., Tipologija i klassifikacija lesov evropejskoj Rossii: metodicheskie podhody i vozmozhnosti ih realizacii (Typology and classification of European Russian forests: methodological approaches and potentialities of their realization), Lesovedenie, 2006, No 1, pp. 34-48.

Zaugol’nova L.B., Tipologicheskogoe raznoobraziya lesnoj rastitel’nosti (Typological diversity of forest vegetation), Monitoring biologicheskogo raznoobraziya lesov Rossii, А.S. Иsaev (Ed.), Moscow: Nauka, 2008, pp. 174-179.

Zav’yalov N.A., Bobry (Castor fiber, C. canadensis) – sredoobrazovateli i fitofagi (Beavers (Castor fiber, C. canadensis) – founders of habitats and phytophages), Uspekhi sovremennoj biologii, 2013, Vol. 133, No 5, pp. 502-528.

Zav’yalov N.A., Krylov A.V., Bobrov A.A., Ivanov V.K., Dgebuadze Yu.Yu., Vliyanie rechnogo bobra na ekosistemy malyh rek (Influence of river beaver on ecosystems of small rivers), Moscow: Nauka, 2005, 186 p.

Zav’yalova L.F., Biogeocenoticheckaya rol’ kabana v Darvinskom zapovednike i ego znachenie v sosednih sel’hozugod’yah (Biogeocenotic role of wild boar in the Darwin nature reserve and its importance in neighboring farmland), In: Nauchnye issledovaniya v zapovednikah i nacional’nyh parkah Rossii (federal’nyj otchet za 1992–1993 gody) (Scientific research in reserves and national parks of Russia (federal report 1992-1993)), Moscow, 1997, pp. 99-100.

Zenyakin S.A., Onipchenko V.G., Opyt ocenki masshtabov royushchej deyatel’nosti kavkazskogo krota (Talpa caucasica Satunin) na al’pijskom lugu Teberdinskogo zapovednika (Burrowing activity of the caucasian mole (Talpa caucasica Satunin) on an alpine meadow in the Teberda nature reserve), Byulleten’ MOIP. Otdel biologicheskij, 1997, Vol. 102, Issue 3, pp. 52-53.

Zhang D.Q., Hui D., Luo Y., Zhou G., Rates of litter decomposition in terrestrial ecosystems: global patterns and controlling factors, Journal of Plant Ecology, 2008, Vol. 1, No 2, pp. 85-93.

Zhang C., Mora P., Dai J., Chen X., Giusti-Miller S., Ruiz-Camach N., … & Lavelle P., Earthworm and organic amendment effects on microbial activities and metal availability in a contaminated soil from China, Applied Soil Ecology, 2016, Vol. 104, pp. 54-66.

Zhang B., Lu X., Jiang J., DeAngelis D.L., Fu Z., Zhang J., Similarity of plant functional traits and aggregation pattern in a subtropical forest, Ecology and Evolution, 2017, Vol. 7, No 12, pp. 4086-4098.

Zhu J., Lu D., Zhang W., Effects of gaps on regeneration of woody plants: a meta-analysis, Journal of Forestry Research, 2014, Vol. 25, No 3, pp. 501-510.

Zimov S.A., Pleistocene park: return of the mammoths ecosystem, Science, 2005, Vol. 308, No 5723, pp. 796-798.

Zimov S.A., Zimov N.S., Tikhonov A.N., Chapin III F.S., Mammoth steppe: a high-productivity phenomenon, Quaternary Science Reviews, 2012, Vol. 57, pp. 26-45.

Zlotin R.I. Hodasheva K.I., Rol’ zhivotnyh v biologicheskom krugovorote lesostepnyh ekosistem (The role of animals in the biological cycle of forest-steppe ecosystems), Moscow: Nauka, 1974, 217 p.

Zryanin V.A., Vliyanie murav’ev roda Lasius na pochvy lugovyh biogeocenozov (Effects of ants of the genus Lasius on soils of meadow biogeocenoses), Uspekhi sovremennoj biologii, 2003, Vol. 123, No 3, pp. 278-287. 

Reviewer: PhD in biology, leading researcher V.N. Korotkov

]]> https://jfsi.ru/4-1-2021/ Mon, 05 Apr 2021 08:53:01 +0000 https://jfsi.ru/?p=4077 DOI: 10.31509/2658-607x-2021-1

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Original Russian Text © 2020 E.V. Ruchinskaya, A.V. Gornov published in Forest Science Issues Vol. 3, No. 4, pp. 1-25

E.V. Ruchinskaya^*, A.V. Gornov

Center for Forest Ecology and Productivity of the Russian Academy of Sciences

Profsoyuznaya st. 84/32 bldg. 14, Moscow 117997, Russian Federation

^*E-mail: elena.ruchinskaya@mail.com

Received 01.11.2020

Accepted 14.12.2020

In the zone of broad-leaved forests of the European Russia, steppe meadows have been preserved showing rich floristic composition and making a significant contribution to the biological diversity of the territories. Bryansk oblast is one of the forest regions in Russia where such meadows are found. Here, steppe meadows with high floristic diversity and a large number of rare plant species have survived. Trees from surrounding forest areas are constantly encroaching on these meadows. Most of the young trees die from regular grass fires and economic activity. However, some individuals survive and reach a generative state, becoming relatively resistant to ground fires. The influence of single trees on the floristic diversity of steppe meadows was studied at two levels of living system organization – coenotic and population levels. Polydominant steppe meadows and polydominant steppe meadows with single generative trees were studied at the coenotic level; and coenopopulations of Iris aphylla, Anemone sylvestris, and Anthericum ramosum were studied at the population level. Collecting the material, we used different methods: geobotanical, demographic, and measurements of environmental factors (illumination, slope steepness, and the frequency of grass fires). Polydominant steppe meadows were found to be were preserved in the middle part of steep slopes unsuitable for haymaking and grazing and subjected to infrequent grass fires. These communities have high floristic diversity and stable coenopopulations of model species. Ontogenetic spectra of Anemone sylvestris, Anthericum ramosum, and Iris aphylla are of the complete left-hand type with the maximum number of individuals. Single trees (Quercus robur, Tilia cordata) have controversial influence on the vegetation of polydominant steppe meadows. On the one hand, with the introduction of trees, species diversity of communities increases. This is due to the fact that trees offer resting places and shelter for birds that spread plant diaspores. On the other hand, mature trees shade the herb cover. This leads to cover reduction and occurrence of steppe and dry meadow species, as well as affects their population structure. The ontogenetic spectrum of Anemone sylvestris is still complete, whereas that of Iris aphylla becomes incomplete, and the spectrum of Anthericum ramosum becomes unfinished.

Key words: steppe meadow, single trees, floristic diversity, coenopopulations, ontogenetic spectrum, state of coenopopulations, Anemone sylvestris, Anthericum ramosum, Iris aphylla

Steppe meadows have survived in the zone of broad-leaved forests of the European Russia (Bulohov, 1977, 2001; Bosek, 1980; Skvorcov, 1982; Averinova, 2010; Semenishhenkov, 2010, 2012; Evstigneev et al., 2011; Panasenko et al., 2013, 2015, etc.). These communities, in general, have rich floristic composition and make a significant contribution to the biological diversity of the territories. However, due to human economic activity and grass fires, such coenoses are in danger of extinction (Zelenaja …, 2012; Evstigneev et al., 2018a; Ruchinskaya, 2019). Woody plants from the surrounding forest areas are constantly encroaching on the steppe meadows preserved in the zone of broad-leaved forests. Most of the young trees die from regular grass fires and economic activities such as haymaking, grazing, etc. However, some individuals survive and go into a generative state (Evstigneev et al., 2018a). Mature trees are relatively resistant to ground fires: their renewal buds are located high and the thick crust of the trunk protects the cambium (Serebrjakov, 1962). Single trees affect the growing conditions of other plants in the meadows. It is known that in phytogeneous fields of trees, illumination, air temperature and humidity, soil temperature and humidity, the amount of precipitation penetrating through the crown, quality of litter, concentration of nutrients and other soil characteristics change significantly (Uranov, 1965; Samojlov, 1983; Nikonov et al., 2002; Ipatov, 2007; Zhuravleva et al., 2012; Orlova et al., 2016). In addition, single trees attract animals of different ecological groups, e.g. soil invertebrates, mouse-like rodents, birds, etc. (Manning et al., 2006; Prevedello et al., 2018). On the one hand, these influence the growing conditions of plants, and on the other hand, they participate in the creation of both intracoenotic and intercoenotic flows of diaspores. Therefore, the objective of this work is to consider the influence of single trees on the floristic composition and the state of coenopopulations of some rare plant species in the steppe meadows.

MATERIALS AND METHODS

The research was carried out in the south-east of Bryansk oblast within the Melovitskie Slopes natural monument (Figure 1). The site is located in Komarichsky-Sevsky physiographic region. It consists of elevated loess plains with ravines, gullies, slopes and outcrops of carbonate rocks on the western offsets of the Central Russian Upland. Botanically and geographically, the territory belongs to the Eastern European Province of the European broad-leaved forest region (Rastitel’nost’…, 1980). Komarichsky-Sevsky district has temperate continental climate. The mean annual temperature is 5.4 ^οС. The duration of the warm season with above-freezing temperatures is 228 days; the growing season with the temperature above + 5°C is 188 days. Mean annual precipitation is 613 mm; the mean precipitation in the warm season is 342 mm (Prirodnoe …, 1975).

The research was carried out at two levels of living system organization, i.e. at the coenotic and population level. Polydominant steppe meadows and polydominant steppe meadows with single generative trees were studied at the coenotic level. At the population level, the objects of the study were coenopopulations of model plant species Iris aphylla L., Anemone sylvestris L., and Anthericum ramosum L. Iris aphylla is a short rhizome rosette spring-flowering summer-green plant (Figure 2, A). It is a geophyte. Anemone sylvestris is a perennial herbaceous spring-flowering summer-green short rhizome plant (Figure 2, B). It is a hemicryptophyte and geophyte. Anthericum ramosum is a perennial herbaceous summer-green summer-flowering short rhizome plant (Figure 3). It is a hemicryptophyte and geophyte. These species were chosen due to the fact that they are rare, endangered and listed in Red Books of many regions (Krasnaja…, 2002, 2004, 2015, 2016, etc.). Moreover, Iris aphylla is listed in the Red Book of Russia (2008).

Figure 1. Location of the Melovitskie Slopes natural monument. The green line represents the boundaries of the research object. Background satellite imagery by Microsoft Bing Maps

The following research methods were used: geobotanical, demographic, statistical, and measurements of habitat factors. Relevés were made on plots of 100 m² in 11-fold repetition for each community type. A complete floristic list was compiled at each plot. Species participation was evaluated as scores according to the cover-abundance scale proposed by J. Braun-Blanquet (Mirkin et al., 1989). Species richness and species density were used to assess the species diversity of communities. Species richness is the total number of species in a community, which is obtained on the basis of 11 relevés. Species density is the average number of species per unit area. The names of vascular plants were given according to The Plant List international database (http://www.theplantlist.org/). For relevés analysis of communities, ordination was carried out using Detrended Correspondence Analysis (DCA). This method works successfully with heterogeneous data of relevés (Dzhongman et al., 1999). PC-ORD software was used for calculations. Demographic research was based on ontogenesis periodization proposed by T. A. Rabotnov (1950) and supplemented by A.A. Uranov (1975) and other scientists (Cenopopuljacii …, 1988). Ontogenesis is divided into stages that show morphological and functional differences. Individuals belonging to the same ontogenetic state are grouped together: j – juvenile, im – immature, v – virginile, g₁ – young generative, g₂ – mature generative, g₃ – old generative, ss – sub-senile, s – senile. Ontogenetic states of the model species were determined on the basis of publications (Evstigneev et al., 2018; Ruchinskaya, 2019). The state of coenopopulations was estimated using the number, density, and type of the ontogenetic spectrum. Number is the number of individuals in the study area (Chernova, Bylova, 2007). Population density is the average number of individuals per unit area (Odum, 1986; Cenopopuljacii …, 1988). The type of the ontogenetic spectrum was named according to the classification proposed earlier (Zaugol’nova, 1994b). In the meadows and under the trees, the illuminance was measured hourly with a light meter on a cloudless June day from 10 a.m. to 6 p.m. Illuminance in lux was converted to a percentage of the total illuminance, which was measured in the open space. The slope steepness was measured using a Nikon Forestry Pro rangefinder. The frequency of grass fires was determined by the age of shoots of formation in shrubs (Frangula alnus Mill., Corylus avellana L.). These shoots emerge from dormant buds located in the basal part of the shrub. The former aboveground shoots were destroyed due to fire damage (Figure 4).

RESULT AND DISCUSSION

Polydominant steppe meadows were preserved in the middle part of steep slopes hardly suitable for haymaking and grazing (Figure 5). Grass fires mainly occur once every two years. They limit the introduction of woody plants as young tree species are most vulnerable. For instance, seedlings and juvenile oak plants often die during grass fires (Komarov, 1951). As a result, polydominant communities with high species diversity are formed (Table 1; Suppl. materials). These coenoses are unique since they include species that are characteristic of steppe communities: Ajuga genevensis L., Anemone sylvestris, Aster amellus L., Astragalus cicer L., Campanula sibirica L., Prunus cerasus L., Galium tinctorium L., G. verum L. etc. The ecological-coenotic structure is dominated by plants of the dry meadow group, which also includes the above-named steppe plants. Moist meadow (Festuca pratensis Huds., Hypericum maculatum Crantz, Succisa pratensis Moench, Thalictrum lucidum L. и др.), nemoral forest-edge (Brachypodium pinnatum (L.) Beauv., Peucedanum cervaria (L.) Cusson ex Lapeyr, Laserpitium latifolium L., Lathyrus pisiformis L., L. sylvestris L., Pyrethrum corymbosum (L.) Scop.), and nitrophilous forest-edge (Rubus caesius L. and Valeriana officinalis L.) plants are often found as well. Small participation is typical of forest species, i. e. nemoral – Convallaria majalis L., Corylus avellana, Quercus robur L., Viola mirabilis L., boreal – Frangula alnus, and piny – Pteridium aquilinum, Solidago virgaurea L., and Viola collina Besser. Diaspores of forest and forest-edge species are brought here by animals and wind from the neighbouring pine forest. Moist meadow and nitrophilous species are brought from floodplain communities adjacent to the slope.

Table 1. Characteristics of communities on the steppe slopes. Melovitskie Slopes natural monument

Note. M is the arithmetic mean, and σ is the standard deviation. Communities: 1 – polydominant steppe meadows, 2 – polydominant steppe meadows with single generative trees

Iris aphylla is one of the predominant species in the herb layer of polydominant steppe meadows of the Melovitskie Slopes. Population density of Iris aphylla is 82 plants per 1 m². The ontogenetic spectrum is complete single-peak with a maximum at v and g_н plants (Figure 6, 1a). Iris aphylla is well adapted to high illuminance of open spaces due to the structure of its leaves: they are flattened laterally and vertically oriented (Evstigneev et al., 2018b). Seed renewal of Iris aphylla is facilitated by the activity of animals such as ants and mouse-like rodents that inhabit the slopes and create disturbances. These microsites are characterized by sparse herb cover, loosened substrate, increased aeration and soil temperature, and significant microbiological activity (Zrjanin, 2003; Dauber, Wolters, 2000; Kostrakiewicz, 2004, etc.). For example, a population locus consisting of 10 juvenile plants was found in a 0.03 m² earth ejections of the mouse-like rodent. The spread of Iris aphylla diaspores is facilitated by ants (Figure 7). R.E. Levina (1957) states that fresh seeds attract these animals with sweet, sticky liquid that is contained in the shell. Our observations showed that ants also spread dry seeds (Evstigneev et al., 2018b).

Anthericum ramosum is a codominant species in the herb layer of steppe meadows. Population density of Anthericum ramosum is 56 plants per 1 m². Ontogenetic spectrum is complete, left-hand type, single-peak with a maximum at v and g_н plants (Figure 6, 2а). The formation of the maximum at v and g_н plants is determined by the following: 1) short duration of j and im states; 2) recruitment of plants resting from flowering; 3) recruitment of v with plants of vegetative origin formed as a result of disintegration of g₂ plants.

Figure 2. Model plants species in steppe meadows of the Melovitskie Slopes natural monument: А – Iris aphylla, B – Anemone sylvestris. Photo by A.V. Gornov

Figure 3. Model plants species in steppe meadows of the Melovitskie Slopes natural monument: А, B – Anthericum ramosum. Photo by E.V. Ruchinskaya

Figure 4. Coppice shoots of burnt sour cherry (Prunus cerasus). A – general appearance of the shrub, B – base of the shrub. 1 – stump of a burnt perennial shoot, 2 – dead burnt biennial coppice shoot, 3 – live annual shoot that woke up from a dormant bud after a ground fire in the spring (from: Ruchinskaya, 2019)

Figure 5. Polydominant steppe meadows in the territory of the Melovitskie Slopes natural monument. Photo by A.V. Gornov

Figure 6. Ontogenetic spectrum of coenopopulations of model plant species in steppe meadows. 1 – Iris aphylla, 2 – Anthericum ramosum, 3 – Anemone sylvestris. The X axis shows ontogenetic states, and the Y axis – the proportion of individual plants, %. Circled is population density (the number of plants per 1 m2) is shown. Communities: а – polydominant steppe meadows, b – polydominant steppe meadows with single generative trees. Ontogenetic states of trees: j – juvenile, im – immature, v – virginile, gн – temporarily not flowering generative plant, g1 – young generative, g2 – mature generative, g3 – old generative, ss – subsenile, s – senile

Figure 7. Dispersal of fresh Iris aphylla seeds by the red forest ant (Formica rufa). Photo by E.V. Ruchinskaya

Anemone sylvestris can be both an assectator and a codominant in the herb layer of steppe meadows. Population density of A. sylvestris is 75 plants per 1 m². Ontogenetic spectrum is complete left-hand type with a maximum at im plants (Figure 6, 3a), the density of which is 27 trees per 1 m². No A. sylvestris individuals of seed origin was found in the studied community. Therefore, the spectrum can be called vegetative and complete. High population density and the complete ontogenetic spectrum are determined by the biology of A. sylvestris. Large number of plants of the pregenerative state is due to the ability of A. sylvestris to vegetative reproduction with deep rejuvenation (Figure 8). Vegetative individuals develop from buds that appear on horizontal adventitious roots (Starostenkova, 1986; Barykina, Potapova, 1994). The beginning of the growth season in early spring, before the herb layer rises, contributes to the accumulation of a sufficient amount of macronutrients required for the formation of generative organs in plans. It is worth noting that the absence of seed individuals is evidence of adverse conditions for the coenopopulation. Apparently, this is due to the spread of fire on the slopes, which destroys young seed individuals of A. sylvestris.

Figure 8. Vegetative renewal of Anemone sylvestris: A – generative individual with a root shoot and adventitious buds on the root (from: Barykina, Potapova, 1994, as supplemented), B – juvenile and virginile individuals of root shoot origin (from: Gornov et al., 2013). j – juvenile individual, g – generative individual, v – virginal individual, r m p – root of the parent plant, rh – rhizome, a b – adventitious bud

Polydominant steppe meadows with single generative trees. On the slopes, there are single Quercus robur and Tilia cordata generative trees (Figure 9), which survived fire during their virginile stage. Mature oaks and linden trees are relatively resistant to ground fires: their renewal buds are located high, and the thick crust of the trunk protects the cambium (Serebrjakov, 1962). The steepness of the slope and the frequency of grass fires are similar to polydominant steppe meadows. Ordination of relevés divided polydominant steppe meadows and polydominant steppe meadows with single trees into distinct groups (Figure 10). The communities differ in the maximum values of species richness and species density (Table 1; Suppl. materials). High species diversity is due to several factors. First, in the past, the communities were not subjected to active grazing or haymaking, as they are also located on steep parts of the slopes. Second, single trees offer resting places and shelter for many animals, including birds. These are known to disperse seeds of meadow and forest plants (Manning et al., 2006; Prevedello et al., 2018). As a result, communities with free-standing trees have higher species richness than polydominant steppe meadows. The ecological-coenotic structure of the community is dominated by dry meadow and steppe plants. Under the crowns of single trees, the illuminance is reduced to 60% of the total. Shading reduces the cover of light-loving dry meadow and steppe plants. However, the number of species in this group increases. Allium oleraceum L., Artemisia absinthium L., Carex montana L., Cirsium decussatum Janka, Fallopia convolvulus (L.) Á. Löve, Filipendula vulgaris Moench, Hypericum perforatum L., Silene vulgaris (Moench) Garcke, S. viscaria (L.) Jess., Stachys officinalis (L.) Trevis., Veronica spuria L. etc. appear. In addition, the species composition of other ecological-coenotic groups also expands: Carex hirta L., C. lachenalii Schkuhr, Galeopsis bifida Boenn are found in the moist meadow group; the group of nemoral plants is supplemented by Euonymus europaeus L., Lathyrus niger (L.) Bernh. and Pyrus communis L., and the group of forest-edge nitrophilous group – by Galium aparine L. Apparently, this is due to the activity of animals, primarily birds, that use single trees like resting places and brought diaspores of these plants. It is known that birds actively disperse seeds of many plant species (Levina, 1957; Cramp, 1998, etc.). Thus, thanks to single trees, the polydominant composition of the community with maximum species diversity is maintained. However, shading has an adverse effect on the state of coenopopulations of model plant species.

Figure 9. Polydominant steppe meadows with single trees: А – general appearance of the slope, B – crown of Tilia cordata from above. Photo by A.Yu. Sitnikov

Iris aphylla loses positions in the herb layer of polydominant steppe meadows with single generative trees. Population density is 50 plants per 1 m². This is almost twice as low as in polydominant steppe meadows. A decrease in density is explained by the fact that due to the small amount of light, very few fruiting individuals able to produce viable seeds are formed in Iris aphylla. This leads to a four-fold drop in the number of young seed plants in the coenopopulation. Established plants feature an increased area of the leaf blade (Table 2). This adaptation allows the plants to get more of the scattered light. However, due to the lack of light, most individuals of Iris aphylla develop only to the v-ontogenetic state, and then die. As a result, an incomplete ontogenetic spectrum is formed with a maximum at v plants (Figure 6, 1b). If, over time, the number of trees on the slope increases, and they form a close-canopy area of the forest, the coenopopulation of Iris aphylla will disappear.

Table 2. Length and width of the leaves of Iris aphylla in the light (1) and in the shade (2)

Note. Communities: 1 – polydominant steppe meadows, 2 – polydominant steppe meadows with single generative trees. N – number of measurements, M – arithmetic mean, m_M – error of the arithmetic mean, σ – standard deviation, U – Mann–Whitney test values, p – probability of error. Significant differences in the U test are shown in bold.

Anthericum ramosum shows low cover in the herb layer of polydominant steppe meadows with single generative trees. Under the tree canopy, population density of A. ramosum decreases sharply and only reaches 7 plants per 1 m². This is eight times lower than in polydominant steppe meadows. Here, an unfinished left-hand type ontogenetic spectrum is formed with a maximum at v and g_н individuals (Figure 6, 2b). There are no ss or s individuals in the coenopopulation, which is probably due to the death of plants already in the g₃ state. In addition, the decrease in the population density is explained by the fact that due to a small amount of light, the mortality of j and im individuals increases. The group of v and g_н plants is replenished by single temporarily not flowering generative plants and particles formed as a result of disintegration of g₂ plants. For the same reason, the number of g₃ individuals, which are represented by branching and non-branching particles, increases slightly.

Figure 10. Results of DCA-ordination of relevés of steppe plant communities in the axes of the greatest variation in floristic composition. Communities: 1 – polydominant steppe meadows, 2 – polydominant steppe meadows with single generative trees

The projective cover of Anemone sylvestris is significantly less than in polydominant steppe meadows. Population density decreases six-fold – there are only 12 individuals per 1 m². In the shade, most anemones do not form flower stalks. Therefore, the generative fraction is represented by single fruiting individuals with predominant g₁ plants. They are mainly found on the periphery of the crowns, where there is lateral illumination. As a result, the density of generative plants is ten times less than in the former community. This leads to a significant reduction in the replenishment of the coenopopulation with young plants, since the number of g₂ individuals that produce the largest number of root shoots decreases. Despite this, the ontogenetic spectrum of Anemone sylvestris is still complete and left-hand type. However, it shows an extremely low participation of generative individuals and a shift of the maximum to v plants (Figure 6, 3b). The latter is due to the relatively long duration of the v-ontogenetic state and the insignificant replenishment of the coenopopulation by j and im plants.

CONCLUSION

The maximum species diversity of polydominant steppe meadows is maintained on steep slopes unsuitable for ploughing up, where haymaking and grazing are difficult and fires are infrequent. This contributes to the formation of stable coenopopulations of model species. Their ontogenetic spectra belong to one type – complete left-hand type, with the maximum accounted for by young individuals. The mechanism of formation of this spectrum is species-specific. Thus, individuals of Iris aphylla and Anthericum ramosum are characterized by vegetative reproduction with shallow rejuvenation of particles and frequent breaks in flowering. In addition, the left-hand type structure is provided by high seed productivity, and in case of Anemone sylvestris – by active vegetative reproduction, when plants are deeply rejuvenated. Single trees (Quercus robur, Tilia cordata) have controversial influence on the vegetation of polydominant steppe meadows. On the one hand, with the introduction of trees, species diversity of communities increases. This is due to the fact that trees offer resting places and shelter for birds that spread plant diaspores. On the other hand, mature trees shade the herb cover. This leads to reduced cover and occurrence of steppe and dry meadow species, as well as affects their population structure. The number of individuals of all ontogenetic states is significantly reduced. The ontogenetic spectrum of Anemone sylvestris remains complete, whereas in Iris aphylla it becomes incomplete, and in Anthericum ramosum it becomes unfinished. If, over time, the number of trees on the slope increases, and they form a close-canopy area of the forest, coenopopulations of the model species will gradually disappear from the community.

ACKNOWLEDGEMENTS

The work was carried out as part of the state assignment of the CEPF RAS «Methodological approaches to the assessment of structural organization and functioning of forest ecosystems» (state registration number AAAA-A18-118052400130-7). The authors express their gratitude to Ye.A. Gavrilyuk, senior research officer of the CEPF RAS, for his help in drawing up the map.

REFERENCES

Averinova E.A., Ostepnjonnye opushechnye soobshhestva pamjatnikov prirody “Melovickie Sklony” i “Urochishhe Pechnoe” (Komarichskij rajon Brjanskoj oblasti) (Steppe marginal communities of natural monuments “Melovitsky Slopes” and “Urochishche Pechnoye” (Komarichsky district, Bryansk region)), Izuchenie i ohrana biologicheskogo raznoobrazija Brjanskoj oblasti: materialy po vedeniju Krasnoj knigi Brjanskoj oblasti, Issue 5, Bryansk, 2010, pp. 21-26.

Barykina R.P., Potapova N.F., Biomorfologicheskij analiz vidov roda Anemone L. flory byvshego SSSR v hode ontogeneza (Biomorpological analysis of Anemone L. species during ontogenesis), Byulleten’ Moskovskogo Obshchestva Ispytatelei Prirody, Otdel Biologicheskii, 1994, Vol. 99, Issue 5, pp. 124–137.

Bosek P.Z., O rasprostranenii stepnyh rastenij na territorii Brjanskoj oblasti (On the distribution of steppe plants in the Briansk district), Botanicheskij zhurnal, 1980, Vol. 65, No 6, pp. 829-836.

Bulohov A.D., Stepnye jelementy vo flore Brjanskoj oblasti (Steppe elements in the flora of Bryansk district), Botanicheskij zhurnal, 1977, No. 10, pp. 1505-1511.

Bulohov A.D., Travjanaja rastitel’nost’ Jugo-Zapadnogo Nechernozem’ja Rossii (Herbaceous vegetation of South-West Nonnlack Soil Zone of Russia), Bryansk, Izd-vo BGPU, 2001. 296 p.

Bulohov A.D., Velichkin Je.M., Opredelitel’ rastenij Jugo-Zapadnogo Nechernozem’ja Rossii (Brjanskaja, Kaluzhskaja, Smolenskaja, Orlovskaja oblasti) (Keys to plants of the south-western Non-Black Earth region of Russia (Bryansk, Kaluga, Smolensk, Oryol regions), Bryansk: Izd-vo BGPU, 1997, 320 p.

Cenopopuljacii rastenij (ocherki populjacionnoj biologii) (Plant coenopopulations (essays of plant population biology)), Moscow: “Nauka”, 1988, 184 p.

Chernova N.M., Bylova A.M., Obshhaja jekologija (General ecology), Moscow: Drofa, 2004, 416 p.

Cramp S., The complete birds of the Western Palearctic. UK, 1998. CD-ROM.

Dauber J., Wolters V., Microbial activity and functional diversity in the mounds of three different ant species, Soil Biol. Biochem, 2000, Vol. 32, Issue 1, pp. 93-99.

Dzhongman, R.G.G., Ter Braak S. Dzh. F., Van Tongeren O. F. R., Analiz dannyh v jekologii soobshhestv i landshaftov (Data analysis in community and landscape ecology), Moscow: RASHN, 1999, 306 p.

Evstigneev O.I., Fedotov Ju.P., Gornov A.V., K flore pamjatnika prirody “Sevskie sklony” (Flora of the natural monement “Sevskie sklony”), Izuchenie i ohrana biologicheskogo raznoobrazija Brjanskoj oblasti. Materialy po vedeniju Krasnoj knigi Brjanskoj oblasti, Bryansk, 2011, Issue 6, pp. 45-52.

Evstigneev O.I., Fedotov Ju.P., Kajgorodova E.Ju., Priroda Nerusso-Desnjanskogo poles’ja Brjanskoj oblasti. Redkie rastenija (The nature of the Nerusso-Desnyansky Polesye of the Bryansk region. Rare plants), Bryansk, 2000, 223 p.

Evstigneev O.I., Harlampieva M.V., Ontogenez i sostojanie populjacij Ligularia sibirica (Asteraceae) v nenarushennyh el’nikah na nizinnyh bolotah (Brjanskaja oblast’) (Ontogeny and the population state of Ligularia sibirica (Asteraceae) in undisturbed swamped spruce forest in Bryansk region), Botanicheskij zhurnal, 2014, Vol. 99, No. 6, pp. 670-681.

Evstigneev O.I., Ruchinskaya E.V., Gornov A.V. Izmenenie ostepnennyh lugov v shirokolistvenno-lesnoj zone pod vozdejstviem palov i hozjajstvennoj dejatel’nosti (Brjanskaja obl.) (Changes of steppe meadows in the broad-leaved forest zone under impact of grass burning and economic activities (on the example of the nature monument «Melovitskie sklony», Bryansk region)), Botanicheskij zhurnal, 2018a, Vol. 103, No 12, pp. 1552-1564, doi: 10.1134/S0006813618120049.

Evstigneev O.I., Ruchinskaya E.V., Gornov A.V., Ontogenez i sostojanie cenopopuljacij Iris aphylla (Iridaceae) v Brjanskoj oblasti (Ontogeny and state of coenopopulation of Iris aphylla (Iridaceae) in the Bryansk region), Botanicheskij zhurnal, 2018b, Vol. 103, No. 2, pp. 207-223, doi: 10.1134/S0006813618020047.

Gornov A.V., Panasenko N.N., Komarova M.V., Tarasenko A.V., Nekotorye osobennosti populjacionnoj biologii Anemone sylvestris L. (Ranunculaceae) v Brjanskoj oblasti (Some features of the population biology of Anemone sylvestris L. (Ranunculaceae) in the Bryansk region), Bjulleten’ Brjanskogo otdelenija RBO, 2013, No. 1(1), pp. 25-30.

Gornova M.V., Evstigneev O.I., Ontogenez i sostojanie cenopopuljacij Melandrium dioicum (Cariophyllaceae) v vysokotravnyh el’nikah zony shirokolistvennyh lesov (Brjanskaja oblast’) (Ontogeny and state of coenopopulations of Melandrium dioicum (Caryophyllaceae) in tall herb spruce forests in broadleaved forest zone (Bryansk region)), Botanicheskij zhurnal, 2016, Vol. 101, No. 8, pp. 896-910.

http://www.theplantlist.org/ (2020, 15 October)

Ipatov V.S., Fitogennye polja odinochnyh derev’ev nekotoryh porod v odnom jekotope (Phytogenic areas of single trees of some species in the same ecotope), Botanicheskij zhurnal, 2007, Vol. 92, No. 8, pp. 1186-1192.

Komarov N.F., Jetapy i faktory jevoljucii rastitel’nogo pokrova chernozemnyh stepej (Stages and factors of the evolution of the vegetation cover of chernozem steppes), Moscow, 1951, 328 p.

Kostrakiewicz K., Wplyw zwierzat i drobnoustrojuw na populacje kosaccuw (Effect of animals and micro-organisms on Iris sp. populations), Chronmy Przyr. Ojczysta, 2004, Vol. 60, No 2, pp. 34-42.

Krasnaja kniga Brjanskoj oblasti (Red data book of Bryansk region), Bryansk: RIO BGU, 2016. 432 p.

Krasnaja kniga Brjanskoj oblasti. Rastenija, griby (Red data book of Bryansk region. Plants, fungus), Bryansk: ZAO Izd-vo «Chitaj-gorod», 2004, 272 p.

Krasnaja kniga Kaluzhskoj oblasti (Red data book of Kaluga region), Kaluga, OOO “Vash dom”, 2015, Vol. 1, 536 p.

Krasnaja kniga Kurskoj oblasti. Redkie i ischezajushhie vidy rastenij i gribov (Red data book of Kursk region. Rare and vanishing plant and fungi species), Tula, 2002, Vol. 2. 165 p.

Krasnaja kniga Rossijskoj Federacii (rastenija i griby) (Red data book of Russian Federation (plants and fungus)), Moscow: Tovarishhestvo nauchnyh izdanij KMK, 2008, 855 p.

Levina R.E., Sposoby rasprostranenija plodov i semjan (Dissemination ways of fruits and seeds), Moscow: Izd-vo MGU, 1957. 361 p.

Manning A., Fischer J., Lindenmayer D.B., Scattered trees are keystone structures – Implications for conservation, Biol. cons, 2006, No. 132, pp. 311-321.

Mirkin B.M., Rozenberg G.S., Naumova L.G. Slovar’ ponjatij i terminov sovremennoj fitocenologii (Dictionary of concepts and terms of modern phytocenology), Moscow: “Nauka”, 1989. 223 p.

Nikonov V.V., Lukina N.V., Smirnova E.V., Isaeva L.G., Vlijanie Picea obovata i Pinus sylvestris na pervichnuju produktivnost’ nizhnih jarusov hvojnyh lesov Kol’skogo poluostrova (Influence of Picea obovata and Pinus sylvestris trees on the lower layer primary productivity in coniferous forests of the Kola peninsula), Botanicheskij zhurnal, 2002, Vol. 87, No. 8, pp. 107-119.

Odum Ju. Jekologija (Ecology), Vol. 2, Moscow: “Mir”, 1986. 376 p.

Orlova M.A., Lukina N.V., Smirnov V.E., Artemkina N.A., The influence of spruce on acidity and nutrient content in soils of northern taiga dwarf shrub–green moss spruce forests, Eurasian Soil Science, 2016, Vol. 49, No. 11, pp. 1276-1287.

Panasenko N.N., Evstigneev O.I., Fedotov Ju.P., Gornov A.V., K flore pamjatnika prirody «Markovskie gory» (Brjanskaja oblast’) (Flora of the natural monument “Markovskie gory” (Bryansk region), Izuchenie i ohrana biologicheskogo raznoobrazija Brjanskoj oblasti. Materialy po vedeniju Krasnoj knigi Brjanskoj oblasti, Issue 8, Bryansk, 2013, pp. 121-131.

Panasenko N.N., Evstigneev O.I., Gornov A.V., Ruchinskaya E.V., K flore pamjatnika prirody “Melovickie sklony” (Brjanskaja oblast’) (Flora of the Natural Monument “Melovitskie sklony” (Bryansk region)), Bjulleten’ Brjanskogo otdelenija RBO, 2015, Vol. 2, No 6, pp. 17-25.

Prevedello J.A., Almeida-Gomes M., Lindenmayer D.B., The importance of scattered trees for biodiversity conservation: A global meta-analysis, Journal of Applied Ecology, 2018, No 55, pp. 205-214.

Prirodnoe rajonirovanie i tipy sel’skohozjajstvennyh zemel’ Brjanskoj oblasti (Natural zoning and types of agricultural lands), Bryansk, Priok. kn. izd-vo. Brjan. otd-nie, 1975. 611 p.

Rabotnov T.A., Zhiznennyj cikl mnogoletnih travjanistyh rastenij v lugovyh cenozah (Life cycle of perennial herbaceous plants in meadow cenoses), Trudy BIN AN SSSR, Serija 3, Geobotanika, Moscow-Leningrad, 1950, No. 6, pp. 7-204.

Rastitel’nost’ Evropejskoj chasti SSSR (Vegetation of the European part of the USSR), Leningrad: “Nauka”, 1980, 420 p.

Ruchinskaya E.V., Strukturnoe i vidovoe raznoobrazie rastitel’nosti ostepnennyh lugov v zone shirokolistvennyh lesov (na primere pamjatnika prirody “Melovickie sklony”, Brjanskaja obl.), Diss. kand. biol. nauk (Structural and species diversity of vegetation of steppe meadows in the zone of deciduous forests (case study of the natural monument “Melovitsky slopes”, Bryansk region) Candidate’s biol. sci. thesis), Moscow: ILAN RAN, 2019, 197 p.

Samojlov Ju.I., Struktura fitogennogo polja na primere odinochnyh dubov Quercus robur (Fagaceae) (The structure of the phytogeneous field as exemplified by the single oak-trees Quercus robur (Fagaceae)), Botanicheskij zhurnal, 1983, Vol. 68, No. 8, pp. 1022-1034.

Semenishhenkov Ju.A., Kal’cefitnaja travjanaja rastitel’nost’ v Brjanskoj oblasti: sintaksonomija, jekologija i voprosy ohrany (Calcephyte grassy vegetation in Bryansk region: syntaxonomy, ecology and protection), Vestnik VGU. Serija: Himija. Biologija. Farmacija, 2012, No. 1, pp. 149-163.

Semenishhenkov Ju.A., Ostepnennye luga pravoberezh’ja reki Desny – unikal’nye prirodnye kompleksy na granice botaniko-geograficheskih podzon hvojno-shirokolistvennyh i shirokolistvennyh lesov (Steppe meadows on the right bank of the Desna River – unique natural complexes on the border of the botanical-geographical subzones of coniferous-deciduous and deciduous forests), Problemy izuchenija i vosstanovlenija landshaftov lesostepnoj zony. Tula, 2010, Issue 1, pp. 206-216.

Serebrjakov I.G., Jekologicheskaja morfologija rastenij (Ecological morphology of plants), Moscow: “Vysshaja shkola”, 1962, 378 p.

Skvorcov A.K., Kal’cefil’naja flora na juge Pogarskogo rajona Brjanskoj oblasti (Calciphilous flora in the Southern part of the Pogar district, Bryansk region, Byulleten’ Moskovskogo Obshchestva Ispytatelei Prirody, Otdel Biologicheskii, 1982, Vol. 87, Issue 5, pp. 77-83.

Starostenkova M.M., Rod vetrenica (Genus Anemone), In: Biol. flora Moskovskoj oblasti (Biological flora of Moscow region), Moscow: Izdatel’stvo Moskovskogo universiteta, 1976, Isssue 3, pp. 119-138.

Uranov A.A., Fitogennoe pole (Phytogeneous field), In: Problemy sovremennoj botaniki (Challenges of modern botany). Vol. 1, Moscow-Leningrad: «Nauka», 1965, pp. 251-254.

Uranov A.A., Vozrastnoj spektr fitocenopopuljacij kak funkcija vremeni i jenergeticheskih volnovyh processov (Fitotsenopopulyatsy age spectrum as a function of time and energy of wave processes), Nauchnye doklady vysshej shkoly. Biologicheskie nauki, 1975, No. 2, pp. 7-34.

Zaugol’nova L.B., Struktura populjacij semennyh rastenij i problemy ih monitoringa. Diss. dokt. biol. nauk (Seed plant population structure and challenges of their monitoring. Doctor’s biol. sci. thesis), Saint-Petersburg, SPBGU, 1994a, 70 p.

Zaugol’nova L.B., Smirnova O.V., Vozrastnaja struktura cenopopuljacij mnogoletnih rastenij i ee dinamika (Age structure of cenopopulations of perennial plants and its dynamics), Zhurn. obshh. biol, 1978, Vol. 39, No. 6, pp. 849-858.

Zaugol’nova L.B., Smirnova O.V., Komarov A.S., Hanina L.G., Monitoring fitopopuljacij (Phytopopulation monitoring), Uspehi sovremennoj biologii, 1993, Vol. 113, No. 4, pp. 402-414.

Zelenaja kniga Brjanskoj oblasti (rastitel’nye soobshhestva, nuzhdajushhiesja v ohrane) (Green book of the Bryansk region (plant communities that are in need of protection: monography)), Bryansk: “Brjanskij gosudarstvennyj universitet imeni akademika IG Petrovskogo”, 2012, 144 p.

Zhukova L.A., Izmenenie vozrastnogo sostava populjacij lugovika dernistogo na Okskih lugah, Avtoref. diss. kand. biol. nauk (Changes in the age composition of populations of Deschampsia cespitosa in the Oka meadows. Abstract of Candidate’s biol. sci. thesis), Moscow: MPGI im. V.I. Lenina, 1967, 19 p.

Zhuravleva E.N., Ipatov V.S., Lebedeva V.H., Tihodeeva M.Ju., Izmenenie rastitel’nosti na lugah pod vlijaniem sosny obyknovennoj (Pinus sylvestris L.) (Vegetation changes in meadows under the influence of Scots pine (Pinus sylvestris L.)), Vestnik Sankt–Peterburgskogo universiteta, 2012, Ser. 3, Issue 2, pp. 3-12.

Zrjanin V.A., Vlijanie murav’ev roda Lasius na pochvy lugovyh biogeocenozov (Effects of ants of the genus Lasius on soils of meadow biogeocenoses), Uspehi sovremennoj biologii, 2003, Vol. 123, No. 3, pp. 278-287.

Reviewer: candidate of Biological Sciences, Associate Professor Panasenko N.N.

Supplementary materials

Species composition of the Melovitskie Slopes natural monument communities

Note. Communities: 1 – polydominant steppe meadows, 2 – polydominant steppe meadows with single generative trees PO – average occurrence points, Arabic numerals and «+» – points of cover-abundance scale proposed by J. Braun-Blanquet. ECG – ecological-coenotic groups: D-Md – dry meadow, M-Md – moist meadow, Pn – piny (boreal forest-edge), Nm-FE – nemoral forest edge, Nm-Fo – nemoral forest, Nt-FE – nitrophilous forest-edge, Br-Fo – boreal forest.

Original Russian Text © 2020 T.Yu. Braslavskaya, E.V. Tikhonova, E.V. Basova, T.S. Prokazina published in Forest Science Issues Vol. 3, No. 4, pp. 1-23

T.Yu. Braslavskaya^*, E.V. Tikhonova, E.V. Basova, T.S. Prokazina

Center for Forest Ecology and Productivity of the Russian Academy of Sciences

Profsoyuznaya st. 84/32 bldg. 14, Moscow 117997, Russian Federation

*E-mail: t-braslavskaya@yandex.ru

Received 19.10.2020

Accepted 23.11.2020

The formation of databases of digitized vegetation relevés and the publication of content about them promote cooperation between researchers in solving problems of biodiversity analysis, the exchange of the used data, and, thus, the increase in research representativeness. The article is devoted to the review of the origin and use of the database of relevés of forest vegetation and considers the tasks in which it is used. The current stage of work is characterized as follows: improvement of the database structure, features of the stored information, replenishment of the database, issues of administration, and cooperation organization. Based on the analysis of current trends in the vegetation science and taking into account the features of information stored in the database, the relevant scientific problems, for the solution of which the use of the database is promising, and technical tasks that need to be solved to ensure its continued use were formulated.

Key words: boreal and hemiboreal forests, vegetation relevés, electronic database, forest vegetation classification, biodiversity analysis

The formation of databases of digitized vegetation relevés is one of the important aspects of work in the modern vegetation sciences (Mucina, van der Maarel, 1989; Mucina et al., 1993; Matveeva, 2008; Schaminée et al., 2009; Golub, 2011; Dengler et al., 2011; Chytrý et al., 2016; Bruelheide et al., 2019). It expands opportunities to analyze the structure of phytodiversity (at the coenotic and taxonomic levels) and to identify spatial, ecological, and chronological patterns in it, as well as to estimate the environmental significance of various plants. The publication of information on existing databases of vegetation relevés promotes cooperation between researchers and the development of more informed solutions to these problems, by increasing the representativeness of the used data.

Since the opening of the new institute of the Russian Academy of Sciences (1991) – the Center for Forest Ecology and Productivity (hereinafter – CEPF RAS), its employees have been involved in the creation of an electronic database of forest-vegetation relevés, including data from European Russia and neighboring territories (Khanina et al., 1991; Zaugol’nova, Khanina, 1996; Smirnova et al., 2006) The general structure of the database was developed in cooperation with the institutions of the Pushchino Scientific Center of the Russian Academy of Sciences: the Institute of Mathematical Problems of Biology (IMPB of RAS; now a branch of the Keldysh Institute of Applied Mathematics of RAS) and the Institute of Physicochemical and Biological Problems of Soil Sciences of RAS (IPCBPSS of RAS, now a separate division of the Pushchino Scientific Center for biological research of RAS) in the early 1990s. It included 2 data tables and some reference lists (lookup tables) to fill in some fields in the data tables. The GBDSp data table was intended for storing lists of species with values of their projective cover (by the scale of Josias Braun-Blanquet, see below) in different layers of the forest community. The separate fields of this table also indicated the phenological states, the features of the species positions in the community, and the values of heights and diameters for tree species. For the unified input of species names, a coded reference list of Latin names of vascular plants and bryophytes (Komarov et al., 1991; Zaugol’nova, Khanina, 1996; Khanina et al., 1999; Balandin et al., 2000) was developed and linked to the corresponding field of the table, compiled based on current nomenclature reports (Cherepanov, 1995; Ignatov, Afonina, 1992). The GBDescr data table was intended for storing general information about the implementation of relevés (place and date, author, size of the inspected area) and characteristics of ecotopes (position in relief, moisture regime, and soil texture, nature of microrelief, presence, and nature of traces of land-use, etc.) and layers in forest communities (total projective cover). For the unified filling in of fields with ecotope characteristics in this table, reference lists were also used: coded reference lists of terms most commonly used in relevés of plain forests.

The database was implemented in the database management system (DBMS) Data Ease for the MS-DOS operating system (OS) (Khanina, 1997), which supported a specific data storage format. This DBMS allowed creating, storing, and, if necessary, combining many separate sets of relevés with each other, developing procedures for performing routine operations with relevés: for example, calculating various aggregated indicators or exporting data to formats used by other MS-DOS programs. The relevé database interface included two forms for entering and viewing data corresponding to the two main tables. The reference block of the relevé database was gradually supplemented with tables with the characteristics of plant species: points in ecological scales (Vorobiev, 1953; Ramensky et al., 1956; Tsyganov, 1983; Ellenberg, 1974, 1995; Landolt, 1977), information about the types of ecological strategies (Grime et al., 1988), and belonging to ecological-coenotic groups of plant species (Smirnova et al., 2004; Smirnov et al., 2006; Smirnov, 2007). In this regard, the database interface was also supplemented with procedures for calculating the spectra of relevés by the composition of ecological and ecological-coenotic groups, and types of strategies. To calculate the estimates of relevés in environmental scales, data was exported to the text format with field separators (Comma Separated Value – CSV) and transferred to a specialized external program Ecoscale (Grokhlina, Khanina, 2006).

A large number of relevés in the 1990s and early 2000s were collected in cooperation with the Department of System Ecology of Pushchino State Institute of Natural Science. Master’s degree students and postgraduates of the department were trained in methods of geobotanical research, by participating in expeditions under the leadership of the staff of the CEPF RAS, Doctor in Biological Sciences O. Smirnova, and Doctor in Biological Sciences L. Zaugol’nova, and then in the work on entering into the database the relevés made in the expeditions, under the guidance of the database administrator – an employee of the IMPB of RAS, PhD L. Khanina. For several years, geobotanical research was also carried out together with the Department of Biology of the Institute of Natural sciences and Pharmacy of the Mari El State University and the Department of Geobotany of the Faculty of Biology of the Moscow State University. At the CEPF RAS, the database on the Data Ease DBMS platform was used by PhD students and other employees to work with their vegetation relevés. Based on accumulated relevés and using lookup tables and base procedures, the analysis of the ecology of the species (Smirnova et al., 2004; Smirnov et al., 2006; Smirnov, 2007) and plant communities (Smirnova et al., 1997; Zaugol’nova, 1999; Zaugol’nova et al., 1998, 2000a, b; Evaluation of…, 2000; Smirnova, Korotkov, 2001; Zaugol’nova, Bekmansurov, 2004; Smirnova et al., 2006; European…, 2017, Smirnova et al., 2018; Khanina, 2019) was conducted. An important part of the analysis of the relevés was their use in the development of the classification of forest vegetation in European Russia and the Urals based on different approaches: ecological-floristic (Zaugol’nova, Morozova, 2004a, b; Morozova et al., 2008; Zaugol’nova et al., 2009) and ecological-coenotic (Zaugol’nova, Morozova, 2006; Zaugol’nova, 2006-2010; Zaugol’nova, Martynenko, 2012).

One of the incentives for Russian phytocenologists to use electronic databases was the international school on the basics of working with the Turboveg DBMS (Hennekens, 1995), developed by Stephan Hennekens, an employee of the Institut voor Bos en Natuur (Wageningen the Netherlands), held in Ufa (Republic of Bashkortostan, Russia) in 1997. At that time, the Turboveg DBMS was adopted by the international working group European Vegetation Survey as a standard for maintaining vegetation databases and data exchange (Schaminée, Hennekens, 1995; Schaminée et al., 2009). The school was held based on the Bashkir State University together with the University of Lancaster (United Kingdom of Great Britain); E. Tikhonova, one of the authors of this article, took part in the work of this school. Due to the agreement of the Turboveg developer and the Institut voor Bos en Natuur (Wageningen the Netherlands), there was a practice of the free distribution of this DBMS in the countries of the former USSR for scientific and educational purposes, as a result of which, the CEPF RAS began to use it as well.

The widespread adoption of Windows OS and programs written for it with graphical interfaces that provide the average user with procedures for solving a wide range of routine tasks has led to the emergence of a user community who prefer working with data in such programs. An important step in the development of electronic databases of vegetation relevés was the release of the Windows version of the Turboveg DBMS (Hennekens, Schaminée, 2001). In the 2000s, phytocenologists of the CEPF RAS used the Turboveg and MS Access DBMS developed for Windows, and in parallel converted most of the old sets of relevés from the Data Ease format to the text format with field separators (csv or txt formats).

The purpose of this paper is to present the prospects for further development of the database and plans for its use, based on what has been done from the beginning of the 2000s to the present.

MATERIALS AND METHODS

To write this article, the authors discussed and summarized the accumulated experience of working with the database of vegetation relevés of the CEPF RAS and improving its structure, compiled a description of its current content, analyzed scientific publications on the trends in the development and application of electronic databases of vegetation relevés in Russia and abroad, and current problems of vegetation science.

RESULTS

Since the late 1990s, collecting of relevés in field expeditions has been carried out by PhD students and employees of the CEPF RAS. Since the beginning of the 2000s, in the preparation of the monograph «Eastern European Forests: Holocene history and modernity» (2004) and electronic resources «Forest coenofond within European Russia» (Zaugol’nova, 2006–2010) and «Guide on forest types in European Russia» (Zaugol’nova, Martynenko, 2012), the base has also been expanded with digitized relevés and summary tables, relevés of various publications (see the list in Appendix).

For use in expeditions, a geobotanical relevé form has been composed (Methodological…, 2010: pp. 358–363), which allows formalizing and unifying the characteristics of the conditions in which the community grows. When composing this form, the agreement of the form sections with the relevé database fields was conducted: refined and enhanced base reference lists characterizing the conditions in which the forest community is growing was included in the form as the options of filling, from which it is possible to choose and mark the most appropriate ones. Due to the wide variety of characteristics of conditions that occur in nature, for many of them, some additional fields (in the format of the text of unlimited size) for filling in unformalized notes were created in the database, along with the field associated with the reference list and filled in with standard values.

In the reference list of flora associated with the field of species names in the database table, the nomenclature of bryophytes was updated based on more modern Russian checklists (Ignatov et al., 2006; Konstantinova et al., 2009), and the list of lichens was expanded (Urbanavichjus, Urbanavichene, 2004). To speed up the verification and unification of the nomenclature of species in different sets of relevés, the SpeDiv program is used (Smirnov, 2006), in which it is also possible to calculate the characteristics of the species diversity of relevés, their spectra of ecological-coenottic groups and estimates in various ecological scales.

In 2014, the CEPF RAS registered a database of vegetation relevés in the state Register of Databases under the name «Forest Vegetation of Northern Eurasia» (registration certificate No. 2014620258 dated February 12, 2014; Zaugol’nova et al., 2014). The use of the database is regulated by the approved Regulation on the Bank of forest-vegetation data (phyto-database) of the CEPF RAS. The principles of use are similar to those adopted in the European Vegetation Archive (EVA; Chytrý et al., 2016). To receive relevés, researchers must submit an application to the database administrator, describing the purpose and methods of the planned study, the timing of its implementation, the list of participants, publications that are planned to be prepared based on its results, the total amount of data that will be involved in the analysis, and the characteristics of the requested relevés. The administrator, if the authors of the relevant relevés agree to the transfer, will arrange for the conclusion of an agreement on creative cooperation of the applicants with the CEPF RAS. The relevés are provided for use free of charge, but only for the specified period of execution of the claimed research, in other words, they should not be used after this time and/or for other purposes, and should not be transferred to persons who do not participate in the claimed research. In addition, a mandatory condition for use is the reference of applicants when publishing the results of their research to the CEPF RAS database and the publications of the authors of relevés about the collecting or previous analysis of the same data.

Currently (4Q of 2020), the database contains 5,467 primary relevés, among which 59.4% are original (collected by the CEPF RAS team on expeditions; approximately 200 of these relevés were published afterward) and 40.6% are digitized from Russian and foreign publications of 1928–2012 (about a 16% of the digitized relevés duplicate the contents of other databases known to the authors). Relevés are grouped into sets according to geographical and chronological principles: usually, a set contains materials from one expedition or one publication. The register of relevé sets and the Regulation on the database of relevés are available on the website of the CEPF RAS (URL: http://cepl.rssi.ru/rid-2/). Applications for the use of the database materials can be sent to its administrator Braslavskaya (t.braslavskaya@gmail.com). When preparing the files for sending, the applicants’ wishes about the format are taken into account.

The geographical coverage of the database is represented by the diagrams in the figure. Shown in the legend as a generalized category, the regions of the European part of Russia include Arkhangelsk, Bryansk, Vladimir, Voronezh, Leningrad, Murmansk, Novgorod, Smolensk, Tver, and Yaroslavl Regions, and the Republics of Tatarstan and Udmurtia (each of these regions is presented by less than 3% of the relevés); regions of West Siberia – Tyumen, Krasnoyarsk Territory, Khanty-Mansi and Yamal-Nenets Autonomous Districts. Geographical coordinates were determined by researchers using GPS navigators for 43.6% of the relevés. For 7.7% of the relevés digitized from publications, the coordinates are defined using topographic maps or electronic maps of Google and Yandex (positional accuracy ranged from 1–2 up to 20–30 km). For the rest of the relevés, the coordinates are not specified yet. Fifty-one percent of the relevés contained in the database are made on an accounting area of 100 m², 42.1% – on an area of more than 100 m², 2.7% – on an area of fewer than 100 m²; for 4.2% of the relevés, the accounting area is not known (the latter category includes only relevés from publications). Surface slope and its exposition are specified in 25% of the relevés, verbal description of the relief position is given for 16.1% of the relevés; the presence of bare rock or water on the surface is mentioned for less than 1% of the relevés. Information about the texture and/or other characteristics of the soil are given for less than 2% of the relevés, traces of fires, and/or current or past land-use are given for 8.9%.

А

B

Figure. The geographical data structure in the database «Forest Vegetation of Northern Eurasia». A – distribution by country (I – Russia, II – Ukraine, III – Latvia, IV – Poland, V – Norway). B – distribution by regions of Russia (regions: 1 – Moscow, 3 – Kostroma, 4 – Sverdlovsk, 6 – Vologda, 7 – Perm, 8 – Kirov; republics: 2 – Komi, 5 – Karelia; 9 – other regions of the European part of Russia, 10 – regions of West Siberia)

Researchers and PhD students of the CEPF RAS characterized the participation of species in each layer of the community with values of the projective coverage on the scale of J. Braun-Blanquet (1964): r and + – less than 1%, 1 – 1–5%, 2 – 6–25%, 3 – 26–50%, 4 – 50–75%, 5 – more than 75%. In national publications that appeared before the 1990s, the participation of species is often indicated values of abundance on the scale of O. Drude in the interpretation of V. Sukachev (1972): un (unicus) – one each, sol (solitarius) – in small quantity, sp (sparsus) – small participation (species cover less than 5% of the area), cop (copiosus) – abundantly (big participation: species cover 5% of the area and more) distinguishing the increasing gradations cop1, cop2, and cop3, soc (socialis) – forms a solid background. Researchers of the Komarov Botanical Institute also used a scale with points from 1 to 6 in their relevés (Korchagin, 1940: p. 35). During digitizing, the authors’ values of species abundance in the published old relevés were transferred into values of the Braun-Blanquet scale, taking into account the expertise, resulting from the study of the woods with a similar geographic location and species composition, and the coverage of the respective layer. At that, database executors tried to save information about various types of the origin abundance values in files that have a text format with separators. The lists of identified bryophytes and lichens are given in 53.8% of the relevés. Information about the height and/or diameter of trees – in 14.3%, the age of trees – in 9.3% of the relevés; characteristics of the horizontal structure of the crown cover canopy – in less than 1% of the relevés.

The development of the Turboveg DBMS contributed to the international cooperation of phytocenologists of the CEPF RAS – participation, together with other Russian phytocenologists, in the creation of the European Boreal Forest Vegetation Database (EBFVD), included in the Global Index of Vegetation Databases (GIVD; Dengler et al., 2011) and EVA (Jašková et al., 2020): identifier EU-00-27. As a result of the work done for this purpose, the fraction of relevés of the «Forest Vegetation of Northern Eurasia» database uploaded to the Turboveg DBMS was increased to 50.6%. The primary objective of creating the EBFVD is the development of a harmonized classification of boreal forests in Europe based on an ecological and floral approach.

DISCUSSION

In the initial period of computer use in the analysis of vegetation relevés, it was necessary to simultaneously form databases of the relevés themselves and reference databases for the species found in the relevés (their nomenclature and various characteristics). At the same time, many simple algorithms for analyzing relevés, such as calculating summaries of species diversity or indices based on species characteristics, could be implemented directly in the DBMS interfaces; the development of such tools in databases was considered an important aspect of work (Zaugol’nova, Khanina, 1996). However, different types of multivariate relevé analysis were usually required to be conducted in the specialized programs (Novakovsky, 2006), for example, PCOrd (McCune et al., 2002), Juice (Tichý, 2002), vegan (Oksanen et al., 2013), implementing the stable operation of complex algorithms. After a while, it has also been found useful to combine algorithms for calculating more and more diverse biodiversity indices in specialized programs, such as PAST (Hammer et al., 2001). As a result, an important advantage of database interfaces was not the presence of «built-in» algorithms for any calculations but a variety of automated data layout procedures, including export to specific formats of external programs. This trend was evident when working with a base of vegetation relevés of the CEPF RAS in Windows OS: the calculation of characteristics in the species diversity of the relevés and their spectra of ecological-coenotic groups, as well as estimates of relevés in different ecological scales, began to be conducted in the program SpeDiv (Smirnov, 2006). The program loads lists of species from vegetation relevés in the format of an inflated table, to which they can be exported from various DBMSs. The reference lists used by the SpeDiv program with estimates of plant species in ecological scales and an indication of species belonging to ecological and coenotic groups are the same as in the EcoscaleWin program (Zubkova et al., 2008; Khanina et al., 2014) – the version of Ecoscale modified for Windows.

During the work with vegetation data in the DBMS Data Ease, the task of the storing results of plant-population studies in the database has a small priority, although originally it was planned (Zaugol’nova et al., 1993; Zaugol’nova, Khanina, 1996). When working in the MS Access DBMS, a separate table and reference lists of ontogenetic stages and levels of vitality associated with its fields were developed. Due to the need to combine different types of data in the database (vegetation relevés and the results of population records), the relationships between them were analyzed and a more complex hierarchical structure of the database was developed: information about the geographical tagging of all research points was placed in a separate table – the register of places. Each entry in the register of places is linked to entries from a subordinate table — the register (list) of accounting sites; sites related to the same place may differ in size and the nature of the research conducted on them (Methodological …, 2010). This improvement of the database is possible due to the simple ways provided to the average user by the MS Access DBMS interface, to configure the database structure flexibly including a different number of tables in it and selecting their connecting fields independently. However, to automate many operations that are necessary for working with relevés (for example, exporting to the formats of widely used programs that perform geobotanical data analysis), the procedures that are specially programmed by the user are necessary, and the programming tools built into MS Access do not work consistently enough.

The Turboveg DBMS (Hennekens, Schaminee, 2001) is specialized for working with geobotanical data; therefore, it has been widely used internationally (Schaminée, Hennekens, 1995; Schaminée et al., 2009). To a large extent, it is provided since some parameters of the database structure are rigidly fixed and cannot be changed by an average user. Thus, there can be only two main data tables (a relevé register and an inflated table of species list), reference lists for filling in are provided only in a few standard fields of these tables, and the user cannot change the content of most reference lists. At the same time, several versions of the flora species list are supported, corresponding to the traditions of geobotanical research in different countries, including a version for use in Russia and the former USSR countries, recently updated for the second time (Korablev et al., 2020). The user also has the opportunity to create additional fields of different formats in both data tables so that researchers can preserve any special traditions of performing relevés that they consider important for themselves, and enter this non-standard information into the database. Turboveg serves as a good illustration of the trend towards distinguishing between purely technical data operations and data analysis tools. This DBMS has conveniently automated routine operations of import and manual input of relevés, their storage, layouts, and export to the formats of specialized programs for statistical analysis and classification; the set of implemented procedures is updated periodically in the new versions of the program.

During the further work with the «Forest Vegetation of Northern Eurasia» database, the conversion of various sets of relevés to the Turboveg DBMS format will continue. At the same time, many years of administration experience show that it is necessary to provide for a forced change of the DBMS in connection, for example, with the mass introduction of other operating systems and/or changes in the policy of developers. Thereby, first, storing backups of all sets of relevés and all reference reference lists in the form of the file system in text format with the field separator (csv, txt), allowing the use of data at any event, is still relevant. Second, it requires cooperation with programmers in the development of new specialized DBMS for solving geobotanical problems, taking into account the accumulated experience.

Currently, the main area of using the relevés stored in the database «Forest Vegetation of Northern Eurasia» can be the classification of forest vegetation (mainly North and East European), mapping the areas of its syntaxons. Both of these tasks are still far from a satisfactory solution (Plugatar et al., 2020). The general context in which they are addressed is the analysis of geographical patterns in the biodiversity structure. To do this, it is possible to consider the variation of the values in various indexes calculated based on the species composition of relevés, and in such tasks, the database materials can also be used. Phytocenologists of the CEPF RAS plan to conduct research on these topics independently and participate in them as much as possible, including, as necessary and possible, field research to collect new relevés.

The above summary of the characteristics of ecotopes (the position in the relief, information about the soils, the mode of land-use) shows that the database contains not much information about the conditions in which the studied forests grew. The spatial (by geographical coordinates) linking of the places where relevés were executed with the attribute information of various digitized thematic maps and zonation schemes, as well as spatial digital models of certain landscape components, can help to fill in the missing information to some extent. To do this, it is planned, first, to conduct a targeted search for such thematic map data sources of information about the regions of European Russia and neighboring territories, and, second, to continue determining geographical coordinates for relevés made without the use of GPS navigators but containing detailed information about the georeference. The information on ecotopes obtained in this way, subjected to a thorough expert assessment of its accuracy, can be used in the regional and interregional comparative analysis of biodiversity.

CONCLUSION

The base of vegetation relevés of the CEPF RAS was created and actively used to solve various problems in the study of ecology and geography of plant species and plant communities, the patterns of biodiversity of the forest cover of Northern Eurasia. The accumulated data is still in demand in Russian and international geobotanical research; steps are being taken to organize wider cooperation in the use of this data. Due to the passage of time, their importance may increase if the geographically, environmentally, and chronologically systematic collection of new data and the improvement of tools for technical work with them continue.

ACKNOWLEDGEMENTS

When writing the «Introduction» section, the authors consulted with the employees of the following institutes: the IMPB of RAS – E.M. Glukhova and the IPCBPSS of RAS – Doctor in Biological Sciences M.V. Bobrovskii, who took an active part in the development of the database. A significant contribution to this work was also made by the specialists of the CEPF RAS – E.Yu. Bakun and PhD D.L. Lugovaya. A large number of vegetation relevés were digitized by A.N. Pishchulev, who participated in the development of the «Guide on forest types in European Russia» (Zaugol’nova, Martynenko, 2012). The authors thank the reviewer, PhD L.G. Khanina, for valuable advices that allowed improving the content of all sections of the article. The work was carried out within the framework of the topic of the state task in the CEPF RAS (AAAA-A18-118052400130-7).

REFERENCES

Balandin S.A., Ignatov M.S., Komarov A.S., Onipchenko V.G., Pavlov V.N., Petelin D.A., Khanina L.G., O bazah dannyh i unifikacii botanicheskoj nomenklatury dlja floristicheskih svodok (About databases and unification of botanical nomenclature for floristic monographs), Bjulleten’ Moskovskogo obshhestva ispytatelej prirody, Otdel biologicheskij, 2000, Vol. 105, No. 3, pp. 70-71.

Braun-Blanquet J., Pflanzensoziologie, Grundzüge der Vegetationskunde, Wien–New York, 1964, 865 s.

Bruelheide H., Dengler J., Jiménez-Alfaro B., Purschke O., Hennekens S.M., …, Zverev A., sPlot: a new tool for global vegetation analyses, Journal of Vegetation Science, 2019, Vol. 30, No. 2, pp. 161-186.

Cherepanov S.K., Sosudistye rastenija Rossii i sopredel’nyh gosudarstv (Vascular plants of Russia and neighboring states), Sankt-Petersburg: Mir i sem’ja, 1995, 990 p.

Cherepanov S.K., Sosudistye rastenija SSSR (Vascular plants of the USSR), Leningrad: Nauka, 1981, 509 p.

Chytrý M., Hennekens S.M., Jiménez-Alfaro B., Knollová I., Dengler J., …, Yamalov S., European Vegetation Archive (EVA): An integrated database of European vegetation plots, Applied Vegetation Science, 2016, Vol. 19, No. 1, pp. 173-180.

Cyganov D.N., Fitoindikacija jekologicheskih rezhimov v podzone hvojno-shirokolistvennyh lesov (Phytoindication of environmental regimes within conifer-broadleaved subzone), Moscow: Nauka, 1983, 196 p.

Dengler J., Jansen F., Glöckler F., Peet R.K., De Cáceres M., …, Spencer N., The Global Index of Vegetation-Plot Databases (GIVD): A new resource for vegetation science, Journal of Vegetation Science, 2011, Vol. 22, No. 4, pp. 582-597.

Ellenberg H., Vegetation Mitteleuropas mit den Alpen in okologischer, dynamischer und historischer Sicht, 5, Aufl, Stuttgart: Ulmer, 1996, 1096 s.

Ellenberg H., Zeigerwerte der Gefasspflanzen Mitteleuropas, Gottingen: Goltze, 1974, 97 s.

European Russian Forests: Their Current State and Features of Their History, O.V. Smirnova, M.V. Bobrovsky, L.G. Khanina (eds.), Plant and Vegetation, Vol. 15, Dordrecht: Springer Science+Business Media B.V., 2017, 564 p.

Golub V.B., Ispol’zovanie geobotanicheskih opisanij v kachestve kollekcii obrazcov dlja klassifikacii rastitel’nosti (Using vegetation relevés as a sample collection for classification communities), Rastitel’nost’ Rossii, 2011, No. 17-18, pp. 70-83.

Grime J.P., Hodson J.D., Hunt R., Comparative plant ecology, A functional approach to common british species, London: Unwin Hyman, 1988, 742 p.

Grohlina T.I., Khanina L.G., Avtomatizacija obrabotki geobotanicheskih opisanij po jekologicheskim shkalam (Automatized execution of geobotanical relevés in ecological scales), Principy i sposoby sohranenija bioraznoobrazija, sbornik materialov II Vserossijskij nauchnoj konferencii (Principles and Ways of Biodiversity Conservation: Reports of the 2nd Scientific Conference), L.A. Zhukova (ed.), Yoshkar-Ola, 2006, pp. 87-89.

Hammer Ø., Harper D.A.T., Ryan P.D., Past: Paleontological Statistics Software Package for Education and Data Analysis, Palaeontologia Electronica, 2001, Vol. 4, No. 1, pp. 1-9, available at: http://palaeo-electronica.org/2001_1/past/issue1_01.htm (12, December 2020).

Hennekens S.M., Schaminée J.H.J., TURBOVEG, a comprehensive data base management system for vegetation data, Journal of Vegetation Science, 2001, Vol. 12, No. 4, pp. 589-591.

Hennekens S.M., TURBO(VEG), Software package for input, processing, and presentation of phytosociological data, User’s guide, Instituut voor Bos en Natuur, Wageningen and Unit of Vegetation Science, University of Lancaster, Lancaster, 1995, 54 p.

Ignatov M.S., Afonina O.M., Ignatova E.A., Abolinja A.A., Akatova T.V., …, Zolotov V.I., Spisok mhov Vostochnoj Evropy i Severnoj Azii (Check-list of mosses of East Europe and North Asia), Arctoa, 2006, Vol. 15, pp. 1-130.

Ignatov M.S., Afonina O.M., Spisok mhov na territorii byvshego SSSR (Check-list of mosses of the former USSR), Arctoa, 1992, No. 1, R, 1-85.

Jašková A., Braslavskaya T.Yu., Tikhonova E., Paal J., Rūsiņa S., …, Chytrý M., European Boreal Forest Vegetation Database, Phytocoenologia, 2020, Vol. 50, No. 1, pp. 79-92.

Khanina L.G., Gluhova E.M., Shovkun M.M., Informacionnaja sistema po vidam sosudistyh rastenij Central’noj Rossii (An information system on vascular-plant species of Central Russia), Trudy Zoologicheskogo instituta RAN, 1999, Vol. 278, pp. 62.

Khanina L.G., Grohlina T.I., Gluhova E.M., Novye vozmozhnosti programmy Ecoscale dlja obrabotki geobotanicheskih opisanij po jekologicheskim shkalam (The program Ecoscale: modernized opportunities for analysis of geobotanical relevés in of the ecological scales), Matematicheskaja biologija i bioinformatika: V Mezhdunarodnaja konferencija, Doklady (Mathematical Biology and Bioinformatics: Proceedings of the 5th International Conference), Moscow: Maks Press, 2014, pp. 192-193.

Khanina L.G., Informacionno-analiticheskaja sistema dlja ocenki bioraznoobrazija rastitel’nosti lesnyh territorij srednej polosy Rossii (Information-analytical system for assessment of vegetation biodiversity within woodlands of Middle Russia), Diss. cand. biol. nauk (PhD thesis), Uspenskoe: Institut lesovedenija RAN, 1997, 145 p.

Khanina L.G., Klassifikacija tipov lesorastitel’nyh uslovij po indikatornym vidam Vorob’eva–Pogrebnjaka: baza dannyh i opyt analiza lesotaksacionnyh dannyh (Classification of forest sites by the Vorobjev–Pogrebnyak species indicator tables: database and experience of analysis of forest inventory data), Voprosy lesnoj nauki, 2019, Vol. 2, No. 4, pp. 1-20.

Khanina L.G., Zaugol’nova L.B., Smirnova O.V., Popadjuk R.V., Zubkova E.V., Baza dannyh geobotanicheskih opisanij na JeVM (predlozhenija po standartizacii) (Proposal on standardization of electronic databases of geobotanical relevés), Populjacii rastenij: principy organizacii i problemy ohrany prirody (Plant Populations: the Principles of Organization and Conservation Problems), Yoshkar-Ola, 1991, pp. 98.

Komarov A.S., Khanina L.G., Zubkova E.V., Gubanov V.S., Fomin V.G., O komp’juternoj realizacii naibolee trudoemkih metodov obrabotki geobotanicheskih opisanij (On the computer realization of the most labor-consuming methods of the analysis of vegetation relevés), Nauchnye doklady vyshey shkoly. Biologicheskie nauki, 1991, No. 8, pp. 45-51.

Konstantinova N.A., Bakalin V.A., Andreeva E.N., Bezgodov A.G., Borovichev E.A., Dulin M.V., Mamontov Ju.S., Spisok pechenochnikov (Marchantiophyta) Rossii (Check-list of liverworts, Marchantiophyta, of Russia), Arctoa, 2009, Vol. 18, pp. 1-64.

Korablev A.P., Liksakova N.S., Mirin D.M., Oreshkin D.G., Efimov P.G., Novyj spisok vidov rastenij i lishajnikov Rossii dlja programmy Turboveg for Windows (New species list of plants and lichens of Russia for Turboveg for Windiows), Rastitel’nost’ Rossii, 2020, No. 38, pp. 151-156.

Korchagin A.A., Rastitel’nost’ severnoj poloviny Pechoro-Ilychskogo zapovednika (Vegetation of the north part of the Pechoro-Ilychskiy Reserve), Trudy Pechoro-Ilychskogo gosudarstvennogo zapovednika (Proceedings of the Pechoro-Ilychskiy State Reserve), 1940, No. 2, pp. 3-416.

Landolt E., Okologische Zeigerwerts zur Sweizer Flora, Veroff. Geobot. Inst. Zurich: ETH, 1977, H. 64, s. 1-208,

Matveeva N.V., Pochemu i zachem neobhodimo publikovat’ geobotanicheskie opisanija v otkrytoj pechati (Why and what for is necessary to publish geobotanical releveés in available press), Rastitel’nost’ Rossii, 2008, No. 12, pp. 134-138,

McCune B., Grace J.B., Urban D.L., Analysis of ecological communities, Oregon: MjM Software Design, 2002, 285 p.

Metodicheskie podhody k jekologicheskoj ocenke lesnogo pokrova v bassejne maloj reki (Methodical approaches to ecological evaluation of woodland in a small-river basin), L.B. Zaugol’nova, T.Ju. Braslavskaya (eds.), Moscow: Tovarishhestvo nauchnyh izdanij KMK, 2010, 383 p.

Morozova O.V., Zaugol’nova L.B., Isaeva L.G., Kostina V.A., Klassifikacija boreal’nyh lesov severa Evropejskoj Rossii, I. Oligotrofnye hvojnye lesa (Classification of boreal forests in the North of European Russia. I. Oligotrophic coniferous forests), Rastitel’nost’ Rossii, 2008, No. 13, pp. 61-81.

Mucina L., Rodwell J.S., Schaminée J.H.J., Dierschke H., European Vegetation Survey: current state of some national programmes, Journal of Vegetation Science, 1993, Vol. 4, No. 3, pp. 429-438.

Mucina L., van der Maarel E., Twenty years of numerical syntaxonomy, Vegetatio, 1989, Vol. 81, No. 1, pp. 1-15.

Nosova L.M., Tikhonova E.V., Baza dannyh geobotanicheskih opisanij “Elovye lesa Evropejskoj Rossii” (The geobotanical-relevé database “Spruce forests of European Russia”), Komp’juternye bazy dannyh v botanicheskih issledovanijah, Tret’e soveshhanie (Electornic Databases in Botanical Researches, 3rd Workshop), Sankt-Petersburg: Botanicheskij in-t im. V.L. Komarova, 1997, pp. 77-78.

Novakovskij A.B., Obzor sovremennyh programmnyh sredstv, ispol’zuemyh dlja analiza geobotanicheskih dannyh (A review of the modern programs for the geobotalical analysis), Rastitel’nost’ Rossii, 2006, No. 9, pp. 86-95.

Ocenka i sohranenie bioraznoobrazija lesnogo pokrova v zapovednikah Evropejskoj Rossii (Assessment and conservation of woodlands in nature reserves of European Russia), Moscow: Nauchnyj mir, 2000, 196 p.

Oksanen J., Blanchet F.G., Kindt R., Legendre P., Minchin P.R., …, Wagner H., Package ‘vegan’, Community ecology package, 2013, Vol. 2, No. 9, pp. 1-295.

Plugatar’ Ju.V., Ermakov N.B., Krestov P.V., Matveeva N.V., Martynenko V.B., …, Poljakova M.A., Koncepcija klassifikacii rastitel’nosti Rossii kak otrazhenie sovremennyh zadach fitocenologii (The concept of vegetation classification of Russia as an image of contemporary tasks of phytocoenology), Rastitel’nost’ Rossii, 2020, No. 38, pp. 3-12.

Ramenskij L.G., Cacenkin I.A., Chizhikov O.N., Antipov N.A., Jekologicheskaja ocenka kormovyh ugodij po rastitel’nomu pokrovu (Ecological assessment of forage lands by vegetation), Moscow: Sel’hozgiz, 1956, 472 p.

Schaminée J.H.J., Hennekens S.M., Chytrý M., Rodwell J.S., Vegetation-plot data and databases in Europe: an overview, Preslia, 2009, Vol. 81, No. 3, pp. 173-185.

Schaminée J.H.J., Hennekens S.M., Update of the installation of Turboveg in Europe, Annali di Botanica, 1995, Vol. 53, No. 1, pp. 29-32.

Smirnov V.Je., Jekspertno-statisticheskij podhod k vydeleniju jekologo-cenoticheskih grupp vidov sosudistyh rastenij (Expert-statistical approach to designation of ecological-coenotic groups of vascular-plant species), Diss. kand. biol. nauk (PhD thesis), Institut jekologii Volzhskogo bassejna Rossijskoj akademii nauk, Pushhino, 2007, 110 p.

Smirnov V.Je., Khanina L.G., Bobrovskij M.V., Obosnovanie sistemy jekologo-cenoticheskih grupp vidov rastenij lesnoj zony Evropejskoj Rossii na osnove jekologicheskih shkal, geobotanicheskih opisanij i statisticheskogo analiza (Validation of the ecological-coenotical groups of vascular plant species for European Russian forests on the basis of ecological indicator values, vegetation relevés and statistical analysis), Bjulleten’ Moskovskogo obshhestva ispytatelej prirody, Otdel biologicheskij, 2006, Vol. 111, No. 2, pp. 36-47.

Smirnov V.Je., SpeDiv – programma dlja analiza raznoobrazija rastitel’nosti (SpeDiv – a package for analysis of vegetation diversity), Principy i sposoby sohranenija bioraznoobrazija, sbornik materialov II Vserossijskij nauchnoj konferencii (Principles and Ways of Biodiversity Conservation: Reports of the 2nd Scientific Conference), L.A. Zhukova (ed.), Yoshkar-Ola, 2006, pp. 142-143.

Smirnova O., Zaugol’nova L., Khanina L., Braslavskaya T., Glukhova E., FORUS – database on geobotanic relevés of European Russian forests, Mathematical biology and bioinfomatics, Proceedings of the 1st International Conference, Pushchino, 2006, V.D, Lakhno (ed.), Moscow: MAKS Press, 2006, pp. 150-151.

Smirnova O.V., Bobrovskij M.V., Khanina L.G., Smirnov V.Je., Sukcessionnyj status starovozrastnyh temnohvojnyh lesov Evropejskoj Rossii (Succession status of old-growth spruce and spruce-fir forests in European Russia), Uspehi sovremennoj biologii, 2006, Vol. 126, No. 1, pp. 26-48.

Smirnova O.V., Bobrovsky M.V., Khanina L.G., Smirnov V.E., Old-growth spruce-fir forests in the plain area of the Komi Republic, Russian Journal of Ecosystem Ecology, 2018, Vol. 3, No. 4, pp. 1-25.

Smirnova O.V., Khanina L.G., Smirnov V.Je., Jekologo-cenoticheskie gruppy v rastitel’nom pokrove lesnogo pojasa Vostochnoj Evropy (Ecologic-coenotic species groups in vegetation within forest belt of Eastern Europe), In: Vostochnoevropejskie lesa: istorija v golocene i sovremennost’ (Eastern European Forests: Holocene history and modernity), O.V. Smirnova (ed.), Moscow: Nauka, Vol. 1, pp. 165-175.

Smirnova O.V., Korotkov V.N., Starovozrastnye lesa Pjaozerskogo leshoza severo-zapadnoj Karelii (Old-growth forests of north-west Karelia, Pjaozero forest management unit), Botanicheskij zhurnal, 2001, Vol. 86, No. 1, pp. 98-109.

Smirnova O.V., Popadjuk R.V., Zaugol’nova L.B., Khanina L.G., Ocenka poter’ floristicheskogo raznoobrazija v lesnoj rastitel’nosti (na primere zapovednika “Kaluzhskie zaseki”) (Estimation of floristic losses in forest vegetation: “Kaluzhskie Zaseki” Reserve as an example), Lesovedenie, 1997, No. 2, pp. 27-42.

Sukachev V.N., Rukovodstvo k issledovaniju tipov lesov (Manual on researches of forest types), In: Izbrannye trudy v 3-h tomah (Selected works in 3 volumes), Vol. 1, Leningrad: Nauka, 1972, pp. 15-141.

Tichý L., JUICE, software for vegetation classification, Journal of Vegetation Science, 2002, Vol. 13, No. 3, pp. 451-453.

Urbanavichjus G.P., Urbanavichene I.P., Svodnaja tablica “Lishajniki zapovednikov Rossii” (The combined table “Lichens of Russian nature reserves”), In: Sovremennoe sostojanie biologicheskogo raznoobrazija na zapovednyh territorijah Rossii (Current state of biodiversity within Russian nature reserves), Moscow: IUCN, Ministry of natural resouces of Russian Federation, Biodiversity conservation commission of RAS, 2004, pp. 26-215.

Vorob’ev D.V., Tipy lesov Evropejskoj chasti SSSR (Types of forest communities in the European part of the USSR), Kiev: Izd-vo AN USSR, 1953, 452 p.

Zaugol’nova L.B, Martynenko V.B., Opredelitel’ tipov lesa Evropejskoj Rossii (Guide on forest types in European Russia), 2012, Web-site, available at: http://www.cepl.rssi.ru/bio/forest/ (2020, 5 September).

Zaugol’nova L.B., Bekmansurov M.V., Sukcessionnye processy v rastitel’nom pokrove nemoral’no-boreal’nyh lesov na peschanyh substratah i prognozy ih razvitija (na primere nacional’nogo parka “Marij Chodra”) (Successions and prognoses of vegetation dynamics in nemoral-boreal sandy-soil woodland: an example of the National Park “Marij Chodra”), In: Vostochnoevropejskie lesa: istorija v golocene i sovremennost’ (Eastern European Forests: Holocene history and modernity), O.V. Smirnova (ed.), Moscow: Nauka, 2004, Vol. 2, pp. 125-131.

Zaugol’nova L.B., Byhovec S.S., Barinov O.G., Barinova M.A., Verifikacija ballovyh ocenok mestoobitanija po nekotorym parametram sredy (Verification of scores of habitats by some environmental parameters), Lesovedenie, 1998, No. 5, pp. 48-58.

Zaugol’nova L.B. Cenofond lesov Evropejskoj Rossii (Forest coenofond within European Russia), 2006-2010, Web-site, available at: http://mfd.cepl.rssi.ru/flora/ (2020, 5 September).

Zaugol’nova L.B., Ierarhicheskij podhod k analizu lesnoj rastitel’nosti malogo rechnogo bassejna (na primere Prioksko-Terrasnogo zapovednika) (Hierarchical approach to forest vegetation of small river basin, with special reference to the Prioksko-Terrasnij Reserve), Botanicheskij zhurnal, 1999, Vol. 84, No. 8, pp. 42-56.

Zaugol’nova L.B., Istomina I.I., Tikhonova E.V., Analiz rastitel’nogo pokrova lesnoj kateny v antropogennom landshafte (na primere bassejna reki Zhiletovki, Podol’skij rajon Moskovskoj oblasti) (Analysis of a forest catena in anthropogenic landscape, river Zhiletovka, Podolsk district, Moscow region), Bjulleten’ Moskovskogo obshhestva ispytatelej prirody, Otdel biologicheskij, 2000a, Vol. 105, No. 4, pp. 42-52.

Zaugol’nova L.B., Khanina L.G., Braslavskaja T.Ju., Bakun E.Ju., Gluhova E.M., …, Janickaja T.O., Lesnaja rastitel’nost’ Severnoj Evrazii (baza dannyh) (Forest vegetation of the North Eurasia, electronic database), Svidetel’stvo gos, registracii (state registration certificate), No. 2014620258 (2014, 12 February).

Zaugol’nova L.B., Khanina L.G., Opyt razrabotki i ispol’zovanija baz dannyh v lesnoj fitocenologii (Experience of elaboration and using databases in forest phytocoenology), Lesovedenie, 1996, No. 1, pp. 76-83.

Zaugol’nova L.B., Morozova O.V., Rasprostranenie i klassifikacija nemoral’no-boreal’nyh lesov (Distribution and classification of nemoral-boreal forests), In: Vostochnoevropejskie lesa: istorija v golocene i sovremennost’ (Eastern European Forests: Holocene history and modernity), O.V. Smirnova (ed.), Moscow: Nauka, 2004a, Vol. 2, pp. 13-62.

Zaugol’nova L.B., Morozova O.V., Rasprostranenie i klassifikacija boreal’nyh lesov (Distribution and classification of boreal forests), In: Vostochnoevropejskie lesa: istorija v golocene i sovremennost’ (Eastern European Forests: Holocene history and modernity), O.V. Smirnova (ed.), Moscow: Nauka, 2004b, Vol. 2, pp. 295-330.

Zaugol’nova L.B., Morozova O.V., Tipologija i klassifikacija lesov evropejskoj Rossii: metodicheskie podhody i vozmozhnosti ih realizacii (Typology and classification of European Russian forests: methodological approaches and potentialities of their realization), Lesovedenie, 2006, No. 1, pp. 34-48.

Zaugol’nova L.B., Shutov V.V., Ryzhov A.N., Tikhonova E.V., Ryzhova N.V., …, Shirjaev S.I., Sostav i struktura rastitel’nosti lesnoj kateny v smeshannyh lesah juzhnoj chasti Kostromskoj oblasti (Composition and structure of vegetation along forest catena in mixed forests of the south part of Kostroma region), V.V. Shutov (ed.), Kostroma: Kostromskoj gosudarstvennyj tehnologicheskij universitet, 2000b, 92 p.

Zaugol’nova L.B., Smirnova O.V., Braslavskaja T.Ju., Degteva S.V., Prokazina T.S., Lugovaja D.L., Vysokotravnye taezhnye lesa vostochnoj chasti Evropejskoj Rossii (Tall herb boreal forests of Eastern part of European Russia), Rastitel’nost’ Rossii, 2009, No. 15, pp. 3-26.

Zaugol’nova L.B., Smirnova O.V., Komarov A.S., Khanina L.G., Monitoring fitopopuljacij (Monitoring of plant populations), Uspehi sovremennoj biologii, 1993, Vol. 113, No. 4, pp. 402-414.

Reviewer: PhD, Chief Researcher, Associate Professor Khanina L.G.

Supplementary materials

Publications, relevés of which are digitized and included in the database

«Forest vegetation of Northern Eurasia»

Afanas’eva N.B., Istorija lesnoj rastitel’nosti nacional’nogo parka “Russkij sever” (History of forest vegetation in the National Park “Russian North”), Vologda, Izdatel’stvo “Sad-ogorod”, 2010, 173 p.

Andrienko T.L., Sosnovye lesa Ukrainskogo Poles’ja (Pine forests of the Ukrainian Poles’je), Klassifikacija rastitel’nosti SSSR s ispol’zovaniem floristicheskih kriteriev, Moscow, Izdatel’stvo Moskovskogo universiteta, 1986, pp. 112-121.

Astapova T.N., Denisova G.M., Geobotanicheskoe opisanie travjanistogo pokrova v lesnom massive b. Verhne-Kljaz’minskogo zapovednika (Geobotanical characteristics of herb layer in forests of the former Upper-Kljaz’minskiy Nature Reserve), Uchenye zapiskiMoskovskogo gorodskogo pedagogicheskogo instituta, 1955, Vol. 29, Iss. 3, pp. 85-97.

Aune E.I., Forest vegetation in Hemne, Sor-Trondelag, Western Central Norway, K. norske Vidensk. Selsk. Mus. Miscellanea, 1973, Vol. 12, pp. 1-87.

Avrorin N.A., Kachurin M.H., Korovkin A.A., Materialy po rastitel’nosti Hibinskih gor. Materialy po rastitel’nosti central’noj i zapadnoj chastej Kol’skogo poluostrova (Data on vegetation of the Khibin Mountains – central and western parts of Kola Peninsula), Trudy soveta po izucheniju proizvoditel’nyh sil (Serija Kol’skaja), Moscow, Izdatel’stvo Akademii nauk SSSR, 1936, Iss. 11, pp. 3-93.

Bulohov A.D., Semenishhenkov Ju.A., Shirokolistvenno-elovye lesa jugo-zapadnogo Nechernozem’ja Rossii (Broadleaved-conifer forests in the South-West Nechernozem’je of Russia), Vestnik Brjanskogo gosudarstvennogo universiteta, 2010, No. 4, pp. 118-123.

Bulohov A.D., Semenishhenkov Ju.A., Soobshhestva klassa Querco-Fagetea Br.-Bl. et Vlieger in Vlieger 1937 v Sudost’-Desnjanskom mezhdurech’e (Brjanskaja oblast’) (Communities of class Querco-Fagetea Br.-Bl. et Vlieger in Vlieger 1937 in the Sudost’-Desnjanskoe interfluve, Brjansk Region), Rastitel’nost’ Rossii, 2008, No. 13, pp. 3-13.

Bulohov A.D., Shapurko A.V., Associacii i tipy sosnovyh lesov Vet’minsko-Bolvinskogo mezhdurech’ja (v predelah Brjanskoj oblasti) (Associations and types of pine forests in the Vet’minsko-Bolvinskoe interfluve within Bryansk Region), Vestnik Brjanskogo gosudarstvennogo universiteta, 2010, No. 4, pp. 101-107.

Dylis N.V., Tipy listvennichnikov Juzhnogo Timana (Types of larch forests in the South Timan), Trudy Botanicheskogo instituta Akademii nauk SSSR (Serija 3 – Geobotanika), 1938, Iss. 4, pp. 339-371.

Gorchakovskij P.L., Shirokolistvennye lesa i ih mesto v rastitel’nom pokrove Juzhnogo Urala (Broadleaved forests and their role in vegetation of the South Urals), Moscow, Nauka, 1972, 146 p.

Gorchakovskij P.L., Vazhnejshie tipy gornyh elovyh i sosnovyh lesov juzhnoj chasti Srednego Urala (The most important types of mountain spruce and pine forests in the south part of the Middle Urals), Sbornik trudov po lesnomu hozjajstvu, 1956, Iss. 3, pp. 7-50.

Grozdov B.V., Obnovlenskij V.M., Pochvy i tipy lesa Kalashnikovskogo uchebno-opytnogo lespromhoza Lihoslavskogo rajona Moskovskoj oblasti (Soils and forest types in Kalashnikovskoe experimental-training forestry, Lihoslavl district, Moscow Region), Iss. 1, 1931, pp. 46-99.

Homutova M.S., Ocherk rastitel’nosti vodorazdela rek Nei i B. Kakshi (A study of vegetation within the interfluve between rivers Neya and Bolshaya Kaksha), Uchenye zapiski Moskovskogo gos. pedagogicheskogo instituta imeni V.I. Lenina, 1941, Vol. 30, Iss. 1, pp. 79-99.

Kasprowicz M., Acidophylous oak forests of the Wielkopolska region (West Poland) against the background of Central Europe, Biodiversity Research Conservation, 2010, Vol. 20, pp. 1-138.

Kasprowicz M., Acidophylous oak forests of the Wielkopolska region (West Poland) against the background of Central Europe, Biodiversity Research Conservation, 2010, Vol. 20, pp. 1-138.

Kolesnikov B.P., Lesnaja rastitel’nost’ jugo-vostochnoj chasti bassejna Vychegdy (Forest vegetation in the south-east part of the Vychegda-river basin), Leningrad, Nauka, 1985, 215 p.

Korchagin A.A., Senjaninova-Korchagina M.V., Lesa Mologo-Sheksninskogo mezhdurech’ja (Forests within the Mologa-Sheksna interfluve), Trudy Darvinskogo gos. zapovednika, 1957, Vol. 4, pp. 241-402.

Korotkov K.O. Lesa Valdaja (Forests on the Valday Upland), Moscow, Nauka, 1991, 160 p.

Korotkov K.O., Morozova O.V., Nekotorye lesnye soobshchestva sojuza Carpinion betuli v Podmoskov’e (Some forest communities of the alliance Carpinion betuli in Moscow Region), Moscow, Deponirovano v VINITI (No. 3395-V88), 1988, 33 p.

Kurnaev S.F., Osnovnye tipy lesa srednej chasti Russkoj ravniny (The main forest types within central part of Russian Plain), Moscow, Nauka, 1968, 356 p.

Kurnaev S.F., Tenevye shirokolistvennye lesa Russkoj ravniny i Urala (Shady broadleaved forests within Russian Plain and the Urals), Moscow, Nauka, 1980, 316 p.

Laiviņš M., Classification of dry spruce forest communities in Latvia, Mežzinātne – Forest Science, 2009, Vol. 20, No. 53, pp. 32-59.

Laiviņš M., Classification of dry spruce forest communities in Latvia, Mežzinātne. Forest Science, 2009, Vol. 20, No. 53, pp. 32-59.

Leskov A.I., Fitocenoticheskij ocherk redkolesij bassejna r. Poluja (Phytocoenotic study of woodlands within the Poluy-river basin), Trudy Botanicheskogo instituta Akademii nauk SSSR (Serija 3 – Geobotanika), 1937, Vol. 4, pp. 253-276.

Matuszkiewicz J., Przegląd fitosocjologiczny zbiorowisk leśnych Polski, Cz. 4, Bory świerkowe i jodłowe, Phytocoenosis, 1977, Vol. 6, No. 3, pp. 151-225.

Matuszkiewicz J., Przegląd fitosocjologiczny zbiorowisk leśnych Polski, Cz. 4, Bory świerkowe i jodłowe,  Phytocoenosis, 1977, Vol. 6. No. 3, pp. 151-225.

Petrov V.V., Kuzenkova L.Ja., Rezul’taty izuchenija svjazi mezhdu harakterom lesnoj rastitel’nosti i pochvoobrazujushhimi porodami na jugo-zapade Moskovskoj oblasti (Relationship between forest communities and soil-forming rocks in the south-west part of Moscow Region: results of study), Uchenye zapiski Moskovskogo oblastnogo pedagogicheskogo instituta, 1968, Vol. 181, Iss. 12, pp, 196-205.

Polozov M.B., Solomeshh A.I., Sintaksonomicheskij sostav lesnoj rastitel’nosti juzhnoj Udmurtii. I. Pojmennye lesa (Syntaxonomy of forest vegetation at south extreme of Udmurt Republic: Part 1 – Floodplain forests), Min-vo obshhego i prof. obrazovanija RF, Izhevsk: Udmurtskij gos. un-t (Deponirovano v VINITI, No. 3384-V99), 1999, 37 p.

Porfir’ev V.S., Temnohvojnye shirokolistvennye lesa severo-vostoka Tatarii (Mixed forests at north-east extreme of Tatarstan Republic), Uchenye zapiski Kazanskogo gos. pedagogicheskogo instituta, fakul’tet estestvoznanija, Kazan’, 1950, Iss. 9, pp. 47-117.

Prilepskij N.G., Rastitel’nyj pokrov severo-vostoka Kostromskoj oblasti (bassejna r. Vohmy) (Vegetation at north-east extreme of Kostroma Region: Vokhma-river basin), Dissertacija … kandidata biol. nauk, Moscow, Moskovskiy gos. universitet imeni M.V. Lomonosova, 1992, 354 p.

Rechan S.P., Malysheva T.V., Abaturov A.V., Melanholin P.N., Lesa Severnogo Podmoskov’ja (Forests in the north part of Moscow Region), Moscow, Institut lesovedenija Rossiyskoy Akademii nauk, 1993, 316 p.

Rysin L.P., Slozhnye bory Podmoskov’ja (Broadleaved-pine forests in Moscow Region), Moscow, Nauka, 1969, 107 p.

Rysin L.P., Kovalenko Z.M., O vozmozhnostjah ispol’zovanija metodiki shkoly Braun-Blanke v nashih geobotanicheskih issledovanijah (On the use of Brown-Blanquet’s approach in our geobotanical researhes), Bjulleten’ Moskovskogo Obshchestva Ispytateley Prirody (Otdel boil.), 1968, Vol. 73, Iss. 1, pp. 93-114.

Ryzhova N.A., Struktura i vidovoj sostav rastitel’nosti soobshhestv evropejskogo Severa SSSR (The structure and species composition of plant communities in north of the European part of the USSR), Trudy Komi filiala Akademii nauk SSSR, No. 72, Syktyvkar, 1985, 105 p.

Sambuk F.V., Pechorskie lesa (Forests in the valley of Pechora-river), Trudy Botanicheskogo muzeja Akademii nauk SSSR, 1932, Vol. 24, pp. 63-250.

Semenishhenkov Ju.A., Jekologicheskie varianty nemoral’notravnyh el’nikov na juge podtaezhnoj podzony (Smolenskaja oblast’) (Ecological variants of the nemoral-herb spruce forests in the south part of hemiboreal zone, Smolensk Region), Nauchnye vedomosti Belgorodskogo gosudarstvennogo universiteta (Serija Estestvennye nauki), 2012, No. 9 (128), Iss, 19, pp. 22-30.

Shaposhnikov E.S., Korotkov K.O., Minaeva T.Ju., K sintaksonomii elovyh lesov Central’no-Lesnogo zapovednika. Chast’ 1. Nemoral’nye i travjano-bolotnye el’niki (On syntaxonomy of forests of the Central Forest Nature Reserve: Part 1 – nemoral-herb and swamp forests), Moscow, Deponirovano v VINITI (No. 4083-V88), 1988, 71 p.

Smirnova A.D., Tipy elovyh lesov krajnego severa Kirovskoj oblasti (The types of spruce forests at north extreme of Kirov Region). Ch. 1, 2, Uchenye zapiski Gor’kovskogo gos. universiteta, 1951, Iss, 19, pp, 195-223; 1954, Iss. 25, pp, 195-226.

Smirnova O.V., Zhiznennye cikly, chislennost’ i vozrastnoj sostav populjacij osnovnyh komponentov travjanogo pokrova dubrav (Life cycles, size and age structure of populations of the typical herb species in broadleaved forests), Dissertacija … kandidata biol. nauk, Moscow, Moskovskiy gos. pedagogicheskiy institut imeni V.I. Lenina, 1968, 285 p.

Smirnova Z.N., Lesnye associacii severo-zapadnoj chasti Leningradskoj oblasti (Forest associations in the north-west part of Leningrad Region), Trudy Petergofskogo estestvenno-nauchnogo instituta, 1928, No. 5, pp. 119-263.

Sokołowski A.W., Fitosocjologiczna charakterystyka lasów Puszczy Knyszyńskiej, Prace Instytutu Badawczego Lešnictwa, Warszawa, 1988, No. 682, 117 p.

Sokołowski A.W., Zespoły leśne Nadleśnictwa Zwierzyniec w Puszczy Białowieskiej, Prace Instytutu Badawczego Lešnictwa, Warszawa, 1968, No. 354.

Voropanov P.V., El’niki Severa (Pine forests in Russian North), Moscow–Leningrad, Goslesbumizdat, 1950, 180 p.

Zhuchkov N.D., Rastitel’nost’ rajona Krasnovidovo (Vegetation in the district near Krasnovidovo), Moscow, Izdatel’stvo Moskovskogo universiteta, 1956, 102 p.

]]> https://jfsi.ru/4-1-2021-kostenkonikiforov/ Tue, 30 Mar 2021 06:13:59 +0000 https://jfsi.ru/?p=4142

Original Russian Text © 2020 I.V. Kostenko, A.R. Nikiforov published in Forest Science Issues Vol. 3, No. 2, pp. 1-16

I.V. Kostenko^*, A.R. Nikiforov

Nikitsky Botanical Gardens – National Scientific Center, Russian Academy of Sciences,

Nikitsky Spusk, 52, Yalta 29864, Russian Federation

^*E-mail: ik_64@bk.ru

Received 17.11.2019

Accepted 12.05.2020

About 3 thousand hectares of forest stands were created on the surface of the Crimean mountain plateaus in the middle of the 20th century as a result of afforestation. Studies on the influence of these stands on the properties of mountain meadow soils (Phaeozems) showed that under the forest vegetation, the consolidation of structural aggregates, a decrease in the humus content, and an increase in acidity compared to the soils under the meadow vegetation, which could also affect other soil properties, including the mobility of some metals, were observed. The work objective of this research is to conduct a comparative analysis of the content of Pb, Mn, Cu, and Zn compounds available for biota (1 M ammonium acetate) in the soil under mountain meadows, natural beech forest, and artificial forest stands. Following the obtained results, the available Pb, Mn, and Cu compounds accumulated in the afforested mountain meadow soils relative to the adjacent mountain meadows areas. Thus, the average Pb content in the soil layer of 0–10 cm under the mountain pine stands in comparison with the soil under meadow vegetation was 1.6 times higher, Mn – 1.2 times, Cu – 1.2 times. The Pb content was 2.5 times higher, Mn – 1.5 times higher, and Cu – 1.2 times higher under the silver birch stands. The Pb content was 2.2 times higher, Mn – 2.4 times higher, and Cu – 1.5 times higher under Siberian larch stands. The Pb content was 1.9 times higher, Mn – 1.1 times higher, Cu – 1.3 times higher under the sycamore maple stands, compared to the meadow. Differences between afforested and meadow soils in the content of these elements in most cases were significant, except for the Zn content, signs of accumulation of which under artificial stands were not revealed. The Pb, Mn, and Cu content in the brown forest lessive soil (Luvisols) under the oriental beech corresponded to their concentration under the larch, and the Zn content was significantly higher compared to the soil under all species. The main reason for the increase in the mobility of some elements under tree stands is their transition from immobile forms under the influence of increased acidity of afforested soils. Wood litter due to the low content of trace elements in its composition cannot be a source of their accumulation in the topsoil.

Key words: mountain meadow soils, forest stands, trace elements, acidity, heavy metals

The acidifying effect of artificial forest stands on the soils of former farmland and pastures has been noted in many studies in various natural and climatic zones of the world (Alfredsson et al., 1998; Alriksson, Olsson, 1995; Andersen et al., 2002; Berthrong et al., 2009; Fullerr, Anderson, 1993; Jobbagy, Jackson, 2003; Holubik et al., 2014; Ritter et al., 2003; Wen-Jie et al., 2011). The result of such exposure may be an increase in the concentration of certain trace element compounds available to the biota since pH is a key factor affecting the mobility of the metals in the soil (Reddy et al., 1995; Sauve et al., 1998; Sherene, 2010). Intensive afforestation of the previously almost treeless mountain plateaus (yailas) of the Crimea began in 1957 and about 3 thousand hectares of artificial forest stands were created on the surface of Karabi, Demerdzhi, and Ai-Petrinskaya yailas until the 1970s (Bagrova, Garkusha, 2009). Their main solid woods, consisting of dozens of separate groves of different species, are concentrated on the Ai-Petri plateau. Among the tree species, scots pine dominates, occupying up to 70% of the area, and solid woods of birch, aspen, maple, hazelnut, larch, pear, spruce, and other species are also observed. The stands occupy relatively flat areas, where mountain meadow soils with a thickness of 50–150 cm have been formed.

Earlier, the authors conducted studies on the influence of artificial stands of pine, larch, and birch on the main properties of mountain meadow soils on the Ai-Petri plateau (Kostenko, 2018). It was found that under forest vegetation, an increase in the proportion of large aggregates in the soil structure composition, a decrease in the humus content, and an increase in acidity and the iron content from organo-mineral compounds had happened in comparison with soils under meadow vegetation. The strongest changes in the structural state of the soils were observed under pine stands, changes in acidity and the iron content were observed under larch stands. The strong acidifying effect of larch stands on the soil was also evidenced by the data following Tkachenko (1939) and Khakimov et al. (2005). A decrease in the humus content was observed under all tree species.

The work objective of this paper is a comparative analysis of the content of Pb, Mn, Cu, and Zn compounds available for biota in the soil under artificial forest stands and adjacent areas of mountain meadows.

MATERIAL AND METHODS

Study Object

The Ai-Petri plateau belongs to the western yaila system of the Mountainous Crimea with absolute altitudes of 1100–1300 m above sea level. The climatic conditions on site following the weather station «Ai-Petri» (1180 m) are characterized by the average annual rainfall of 1052 mm, the average annual temperature is 5.7 °C, the average temperature in February is -3.8 °C, in July – 15.5 °C. Most of the precipitation (62%) falls during the cold season from November to March.

The Ai-Petrinsky massif is composed of dense Upper Jurassic limestones, which is the reason for the active development of karst processes. As for the relief, yailas are hilly mountainous plateaus with numerous karst potholes, wells, mines, and caves. Negative landforms are filled with leached products of limestone weathering, which formed the most fertile mountain meadow soils, most of which are currently occupied by artificial forest stands.

According to their morphological structure and properties, these soils are closest to mountain meadow chernozemic soils (Classification …, 1977), which are formed under meadow steppes on sialitic products of limestone weathering. However, typical chernozemic soils are rare since the main mass of full-profile soils of the plateau is characterized by complete leaching of carbonates, the absence of rock fragments in the profile, and acidic and strongly acidic reactions. The most humous virgin variants of these soils, preserved locally in the bottoms of karst potholes, are characterized by the typical dark gray color of the A horizon with a brown tint. Anthropogenically disturbed soils have grayish-brown color (Kostenko, 2014).

In the modern classification of soils of Russia, mountain meadow soils are not represented, and their closest analog is the type of dark humous soils with the AH-C profile (Classification … 2004), which does not cover all the soil diversity of the Crimean yailas.

Following the World Reference Base (WRB) (IUSS Working Group, 2015), mountain meadow soils of the plateau belong to Phaeozems – soils with a dark-colored humous horizon that does not contain secondary carbonates in the profile. Among them, the residual carbonate soils (Calcaric), with signs of clay eluviation (Luvic), underlain by dense rocks from a depth of less than 100 cm (Leptic) and with a dark-colored humous horizon (Chernic) are observed. The meadow and afforested soils described in the article belong to Phaeozems (soil pit 1353) and Leptic Phaeozems (soil pits 1280, 1281, 1332, 1333, 1351, and 1379).

Mountain forest soils of the Crimea, lying from 300 m above sea level along the southern macroslope of the main ridge and on the plateau, are traditionally referred to as brown mountain forest soils or burozems (Dragan, 2004; Polovitskii, Gusev, 1987). Brown forest soils are characterized by weak profile differentiation into genetic horizons, acid reaction, clay deposition in the entire thickness, the absence of clay leaching, or its weak leaching from the upper horizons (Classification …, 1977). Following the classification of 2004, brown soils are classified as structural-metamorphic soils, which are characterized by acid reaction and weak profile differentiation by clay, and following the WRB – as Cambisols. However, it was difficult to determine the type of soil belonging to the beech forest, since it, in the presence of the main signs of brown soil, is characterized by a strong textural differentiation of the profile, most likely caused by active clay lessivation from the upper horizons. In this regard, the soil of the beech forest was classified as a brown forest lessive soil, which is not represented in the soil classifications of Russia but is described as a texturally differentiated soil without a morphologically significant horizon E (Soil science …, 1988). The presence of a clayed argic horizon is the basis for assigning the soil of the beech forest (section 1272) to the Reference Soil Group of Luvisols following the WRB.

In the 21^st century, the territory of Ai-Petri yaila was intensively used for pastures, hayfields, and vegetable gardens for the residents of Yalta before afforestation and then in treeless areas. By the time of the creation of the Yalta Mountain Forest Nature Reserve in 1974, the most fertile soils were severely degraded, so even a long-term stay under the fallow lands did not lead to the restoration of their fertility to the original level. The planting of forests has slowed down the process of humus accumulation, so the organic carbon content in the soils under all artificial stands is lower than under the grassy vegetation in the areas of mountain meadows adjacent to the stands (Kostenko, 2018).

Soil studies were carried out in stands of mountain pine (Pinus kochiana Klotzsch ex K. Koch), silver birch (Betula pendula Roth), Siberian larch (Larix sibirica Ledeb), and sycamore maple (Acer pseudoplatanus L.) planted on the Ai-Petri plateau, according to archival data of the Yalta Mountain and Forest Nature Reserve, in the period from 1958 to 1964. At the time of the study, the age of the stands ranged from 50 to 60 years. To assess the intensity of metal accumulation under forest stands in comparison with natural forests, the same studies were conducted in a natural monodominant beech forest (Fagus orientalis Lipsky), the structure of which is dominated by stands of 7–12 decadal age classes (Plugatar, 2015).

Artificial stands of pine, birch, and maple were monodominant communities, the underwood of which consisted of single specimens of rosehip (Rosa tschatyrdagi Chrshan.) and hawthorn (Crataegus taurica Pojark.). Pine, linden (Tilia cordata Mill.), ash (Fraxinus excelsior L.) with mountain ash (Sorbus aucuparia L.), rosehip, and hawthorn in the underwood were also found in the stands of larch. The trees were planted after plowing the soil according to a thickened scheme of 2 × 0.5–1.0 m, which led to the suppression and loss of a large number of trees by the beginning of this study.

The ground cover under pine, larch, and beech had a projective cover of 5–10%, under birch and maple – 40–70%. The grassy cover under birch stands was dominated with alpine oatgrass (Helictotrichon schellianum (Hack.) Kitag.), orchard grass (Dactylis glomerata L.), common nipplewort (Lapsana intermedia M. Bieb.), milfoil (Achillea setacea Waldst. & Kit.), common agrimony (Agrimonia eupatoria L.), Briza maxima (Briza australis Prokud.), betony (Betonica officinalis L.), couch grass (Elytrigia repens (L.) Gould). Under the thinned stands of pine, tall oat-grass (Arrhenatherum elatius (L.) P. Beauv. ex J.Presl & C.Presl.), orchard grass, and common nettle (Urtica dioica L.) grew. Under the larch stands – false-brome (Brachypodium sylvaticum (Huds.) P. Beauv), orchard grass, broad-leaved willowherb (Epilobium montanum L.), Roberts geranium (Geranium robertianum L.), common nipplewort, wood bluegrass (Poa nemoralis L.), and common nettle. Under the canopy of the beech forest, singular specimens of the sweet woodruff (Galium odoratum (L.) Scop.) were found.

In conditions of high humidity, the litter of broadleaved species and larch mineralizes quite quickly, so the thickness of the litter under them did not exceed 1–2 cm and only under pine reached 4–6 cm.

The areas of the plateau adjacent to the forest stands belong to the meadow steppe, typical for Ai-Petri yaila, in terms of vegetation composition. According to the obtained results, the dominant species for meadow communities are cereals: alpine oatgrass (Helictotrichon schellianum (Hack.) Kitag.), Briza maximum (Brizaelatior Sibth. & Sm.), couch grass (Elytrigia repens (L.) Gould), wood bluegrass (Poa pratensis L.), orchard grass (Dactylis glomerata L.), purple-stem cat’s-tail (Phlum phleoides (L.) H. Karst.), couch grass (Elytrigia strigosa (M. Bieb.) Nevski), as well as milfoil (Achillea setacea Waldst. & Kit.), betony (Betonica officinalis L.), St. John’s wort (Hypericum perforatum L.), wild basil (Clinopodium vulgare L.), creamy strawberry (Fragaria viridis (Duchesne) Weston), hedge bedstraw (Galium mollugo L.), unspotted lungwort (Pulmonaria obscura Dumort.), and some other species.

Methods of Investigation

Soil pits were dug under artificial stands of forest species and beech, as well as on adjacent areas of mountain meadows up to the depth of dense rocks, samples from which were taken in a continuous column after every 10 cm. Also, at each of the variants, at least 5 samples from the 0-10 cm layer were taken.

In the soil samples, the granulometric composition by the pipette method after pyrophosphate dispergation of soils, pH_KCl, hydrolytic or total acidity (Ac_tot) by the pH-metric method, the content of total organic carbon (C_tot) according to Tyurin, and the content of mobile forms of Pb, Mn, Cu, and Zn, a 1M ammonium-acetate extract with a pH of 4.8 (Workshop on Agrochemistry, 2001) were determined.

To study the possibility of the elements entering into the soil by biological transfer, samples of birch, maple and beech leaves were taken in mid-August, and immediately after leaf fall – fresh litter of deciduous species, as well as pine from the upper layer of the litter. The content of Pb, Mn, Cu, and Zn in plant samples was determined after dry ashing of leaves and needles. The determination of all elements was carried out in an atomic absorption spectrometer Kvant-2mt.

Moisture measurements in the soil profile under natural beech forest, larch stands, and meadow vegetation were carried out on October 10, 2014, using an HH2 Delta-T electronic moisture meter.

Statistical processing of the results was carried out using the STATISTICA 6 software package and an online service for calculating the Mann-Whitney criterion.

RESULTS AND DISCUSSION

The results of comparative studies of the content and nature of the profile distribution of trace elements in brown forest soil under beech forest and mountain meadow soil of the Ai-Petri plateau indicate a strong influence of vegetation type on these parameters.

In the profile of meadow soil, the content of most elements is lower, and the spread of values is smaller in comparison with the soil of a beech forest (Figure 1). It is due to the large differences between soils in the main characteristics – the content of clay, organic matter, and pH values (Figure 2), which affect the accumulation of total and mobile forms of trace elements (Tobratov et al., 2007). The differences between the pits in the content of all elements, except Zn, are significant at the level of p ≤ 0.01.

Following the results of multiple correlation analysis (Table 1), the content of mobile Pb in the soil of beech forest is associated with all of these soil factors, Zn – with the content of clay and C_tot, Mn – with the C_tot content, and Cu – with the clay content.

The mobility of metals can also be influenced by the peculiarities of the hydrological regime of soils formed under different types of vegetation. It is obvious that with a comparable amount of precipitation, the humidity of the forest soil in comparison with the meadow will be higher due to the lower evaporation of the shaded surface, which is also protected by a layer of forest litter. The results of measurements of soil moisture in a beech forest in the layers of 10–15, 30–35, and 50–55 cm was, respectively, 25.4±1.8, 35.7±2.2, and 34.4±0.9%, and the meadow – 29.5±1.7, 28.6±2.9, and 27.4±2.5% of the volume of soil at a significance level of differences following the Mann-Whitney criterion ≤ 0.01. As can be seen, due to autumn precipitation, the soil moisture in the layer of 10–15 cm was higher in open areas under meadow vegetation, and deeper layers – under the forest vegetation.

Figure 1. Profile distribution of Pb, Mn, Cu, and Zn compounds available for biota in the soil under natural beech forest, artificial tree stands, and mountain meadows

Figure 2. Profile distribution of clay, Ctot, and pH values in the soil under beech forest and meadow vegetation

Table 1. Results of multiple correlation analysis (n=16)

Note: * – correlation coefficients are significant at the level of p ≤ 0.05, * * – p ≤ 0.01

Judging by the profile distribution of trace elements in the soil of the beech forest (Figure 1), the distribution of Mn is most strongly influenced by humidity, which determines the redox conditions of the soil. In the upper, more desiccated part of the 0–60 cm profile, the Mn content is closely related to C_tot (r = 0.94; n = 7), sharply decreasing with depth. Within the wetter layer of 60–80 cm, the Mn content increases sharply and varies within close values up to 130 cm, indicating that the readily mobile Mn²⁺ compounds are formed under periodically developing reducing conditions (Azarenko, 2013; Orlov et al., 2005) in the middle and lower parts of the profile.

The impact of the forest on the soils under artificial stands occurs only within a few decades from the moment of the formation of a sufficiently closed canopy that prevents the growth of grasses. During this period, a change in some chemical properties of afforested soils has happened, which, however, did not affect the fundamental soil indicators, including the content and nature of the profile distribution of granulometric elements and organic matter. Therefore, despite the change in the concentration of metal compounds available for biota under forest stands, the nature of their profile distribution in most cases is close to the distribution of elements under meadow vegetation (Figure 1). Over the entire profile, the soil under the pine contained more Pb and Zn (Figure 1). The upper part of the profile contained more Mn and Cu under the meadow, in the lower part – under the pine, which is due to the higher acidity of the meadow soil in the layer of 0–40 cm at the site of section 1281 (Ac_tot = 8.9 cmol(+)/kg) compared to the afforested area, where the average profile value of Ac_tot was 7.8 cmol(+)/kg. In this regard, the difference between the pits at the level of p ≤ 0.05 was significant only for Pb.

The soil under birch contained significantly more Pb, Mn, and Cu, especially in the upper part of the profile, with a slight difference in Zn compared to meadow soil. At the bottom of the pit, when moving to the underlying rock, these differences were neutralized (Figure 1), and they were significant for Pb at the level of p ≤ 0.01, and Cu – p ≤ 0.05.

The greatest difference in the content of all the studied elements was observed between meadow soil and the soil under larch, where it was significant at the level of p ≤ 0.05 for Pb, Cu, and Zn and at the level of p ≤ 0.01 for Mn. As can be seen in Figure 1, these differences decreased with depth but persisted up to the underlying rocks.

In comparison with the soil under the meadow, the available Pb compounds were significantly more accumulated in the soil layer of 0–10 cm under stands of all species, Mn – under larch and birch, Cu – under all species except pine, and the difference in the content of Zn between the soils under forest stands and meadow vegetation was unreliable (Table 2). Under the natural beech forest, a significantly higher content of available compounds of all metals, including Zn, was observed.

Table 2. Statistical indicators on the content of elements in the soil layer of 0–10 cm

Note: * – the significance level of the differences following the Mann-Whitney criterion ≤ 0.05, ** – ≤ 0.01.

The main reason for the increase in the mobility of elements under forest stands is the increase in soil acidity, which is observed under all forest species, except for maple, where the differences in the values of Ac_tot in comparison with meadow soil are insignificant (Table 3).

Table 3. Acidity, the content of clay and organic carbon in the soil layer of 0–10 cm

Note: * – the significance level of the differences following the Mann-Whitney criterion ≤ 0.05, ** – ≤ 0.01.

An increase in the mobility of metals with a decrease in pH, including under the influence of tree stands, is described by different authors. The results of studies of Andersen et al. (2004) indicate an increase in acidity under 34-year-old coniferous stands compared to unforested soil, which the authors attribute to an increase in the mobility of Cd and Zn in the upper soil layer under fir, and Cu, Ni, and Pb under spruce. Following the results of studies of Bergkvist (1987), who studied the influence of spruce, beech, and unforested areas on the acidity of the soil solution and the mobility of metals in the lysimetric experiment, the lowest pH values and the highest mobility of metals were observed under spruce, the lowest – under unforested areas. Römkens and Solomon (1998) note that despite the higher total Cd and Zn content in arable soils due to the application of manure and mineral fertilizers, the concentration of these elements in the soil solution was higher in the more acidic soil under the forest.

The content of organic matter either did not affect or had a very weak and multidirectional effect on the content of mobile forms of some metals in afforested soils. Thus, in the soil under the pine, a weak positive relationship with C_tot was revealed only with Zn (r = 0.48; n = 23), under the birch – a negative relationship with Cu (r = -0.53) and Zn (r = -0.63; n = 17). The effect of clay on the metal content in all cases was insignificant.

Closer relationships between soil properties and the metal content in the 0–10 cm layer were observed in the soil under the natural beech forest. According to the data of multiple correlation analysis, the Pb content is associated with all soil indicators with a high degree of significance (R = 0.92; r_clay = 0.58; r_C= -0.70; r_Ac = 0.93; n = 16), manganese – with C_tot and Ac_tot (R = 0.74; r_C = -0.52; r_Ac = 0.67), as well as zinc (R = 0.82; r_C= -0.57; r_Ac = 0.74). Least of all, the content of Cu, associated only with the content of C_tot, depended on soil properties (r = -0.65). The positive correlation with clay and Ac_tot is quite natural since the minerals of the finely dispersed part of the soil are the main source of trace elements, and the acidity affects their mobility. The multidirectional influence of C_tot on the content of the studied metals shows that these bonds can be random since organic matter is not the main source of trace elements in forest soils, but humic and fulvic acids can bind metal ions entering the soil from various sources to insoluble organo-mineral complexes (Orlov et al., 2005).

When analyzing the entire data set for afforested and meadow soils, Ac_tot is the only factor that has a significant impact on the content of the studied elements. Ac_tot correlates most closely with the content of Pb and Mn (Figure 3), which are characterized by the greatest difference between the soils under forest stands and meadow vegetation (Table 2). A less close correlation is observed between Ac_tot and Cu, and the weakest correlation is between Ac_tot and Zn since the amount of zinc with an increase in soil acidity under the influence of forest stands has not changed much.

Figure 3. Effect of Actot on the content of elements in the soil layer of 0–10 cm of mountain meadow, fallow, and afforested soils

Among the reasons for the increase in the content of some elements in the upper layer of the soil under forest stands, the possibility of their introduction with tree litter was also considered. As the results of fresh leaves analysis showed, they contained a particular amount of all the studied elements, except Pb (Table 4), which for several decades of growing artificial stands could lead to the accumulation of Mn, Cu, and Zn in the upper layer of the soil. However, in the fresh litter of deciduous trees, only Zn was found out among all elements, and in much lower concentrations than in live leaves (Table 4). The concentrations of the remaining elements were below the detection limit. Among all the species planted during the plateau afforestation, only pine litter could be a source of trace elements, primarily zinc, entering the soil, but it is not confirmed by the results of determining its content in the soil layer of 0–10 cm (Table 2). At the same time, the high zinc content in the layer of 0–10 cm under the beech (Table 2) and a sharp decrease in its concentration with depth (Figure 1) indicate the possibility of zinc accumulation due to plant litter under the condition of prolonged exposure of the forest to the soil.

Table 4. The content of ash and elements in fallen and fresh leaves and needles

n.d. – not detected.

CONCLUSION

The growth of artificial forest stands on the mountain meadow soils of the Ai-Petri plateau over 60 years caused an increase in their acidity relative to the adjacent areas of mountain meadows and the accumulation of some trace elements.

The greatest difference between the content of elements available for biota in the soil layer of 0–10 cm under forest stands and meadow vegetation was found for Pb and Mn (except for maple), and much smaller for Cu and Zn.

In comparison with the soil of a natural beech forest, only under larch in a layer of 0–10 cm, a higher or similar content of all elements, except for Zn, was observed. The increased Cu content under the pine is explained by its increased content in the soil of the meadow areas adjacent to the pine stands.

The main reason for the increase in the mobility of some elements under tree stands is their transition from immobile forms under the influence of increased acidity of afforested soils.

The absence or extremely low content of elements in the litter excludes the possibility of their accumulation in the upper soil layer under relatively young stands as a result of the mineralization of needles and leaves, but the long-term growth of the beech forest leads to the accumulation of available Zn.

REFERENCES

Alfredsson H., Condron L.M., Clarholm M., Davis M.R., Changes in soil acidity and organic matter following the establishment of conifers on former grassland in New Zealand, Forest Ecology & Management, 1998, Vol. 112, pp. 245-252.

Alriksson A., Olsson M.T., Soil changes in different age classes of Norway spruce (Picea abies (L.) Karst.) on afforested farmland, Plant and Soil, 1995, Vol. 168-169, pp. 103-110.

Andersen M.K., Raulund-Rasmussen K., Hansen H.C.B., Strobel B.W. Distribution and fractionation of heavy metals in pairs of arable and afforested soils in Denmark, European Journal of Soil Science, 2002, Vol. 53, pp. 491-502.

Andersen M.K., Raulund-Rasmussen K., Strobel B.W., Hansen H.C.B., The Effects of Tree Species and Site on the Solubility of Cd, Cu, Ni, Pb and Zn in Soils, Water, Air, and Soil Pollution, 2004, Vol. 154 (1–4), pp. 357-370.

Azarenko Ju.A., Zakonomernosti soderzhanija, raspredelenija, vzaimosvjazej mikrojelementov v sisteme pochva-rastenie v uslovijah juza Zapadnoj Sibir (Regularities of the content, distribution, interconnections of microelements in the soil-plant system in the conditions of the southwestern Siberia), Omsk: Variant-Omsk, 2013. 232 p.

Bagrova L.A., Garkusha L.Ja., Iskusstvennye lesonasazhdenija v Krymu (Artificial Afforestation in Crimea), Jekosistemy, ih optimizacija i ohrana, 2009, Vol. 20, pp. 134-145.

Bergkvist B.O., Leaching of metals from forest soils as influenced by tree species and management, Forest Ecology and Management, 1987, Vol. 22 (1–2), pp. 29-56.

Berthrong S.T., Jobbagy E.G., Jackson R.B., A global meta-analysis of soil exchangeable cations, pH, carbon, and nitrogen with afforestation, Ecological Applications, 2009, Vol. 19, No. 8, pp. 2228-2241.

Dragan N.A., Pochvennye resursy Kryma. Nauchnaja monografija (Soil resources of Crimea. Scientific monograph), 2-e izd., dop. Simferopol’: DOLJa, 2004. 208 p.

Fullerr L.G., Anderson D.W., Changes in soil properties following forest invasion of Black soils of the Aspen Parkland, Can. J. Soil. Sci., April 1993, Vol. 73, No. 4, pp. 613-627.

Holubik O., Podrazsky V., Vopravil J., Khel T., Remes J., Effect of agricultural lands afforestation and tree species composition on the soil reaction, total organic carbon and nitrogen content in the uppermost mineral soil profile, Soil and Water Res., September 2014, No. 9. pp. 192-200.

IUSS Working Group WRB. World Reference Base for Soil Resources 2014, update 2015. International soil classification system for naming soils and creating legends for soil maps. World Soil Resources Reports No 106, FAO, Rome. 192 p.

Jobbagy E.G., Jackson R.B. Patterns and mechanisms of soil acidification in the conversion of grasslands to forests, Biogeochemistry, 2003, Vol. 64, pp. 205-229.

Khakimov F.I., Volokitin M.P., Syroizhko N.P., Changes in gray forest soils under larch stands, Eurasian Soil Science, 2005, Vol. 38. No. 6, pp. 576-585.

Klassifikacija i diagnostika pochv Rossii (Classification and diagnostics of Russian soils), Smolensk: Ojkumena, 2004. 342 p.

Klassifikacija i diagnostika pochv SSSR (Classification and diagnostics of soils of the USSR), M.: Kolos, 1977. 223 p.

Kostenko I.V., Atlas pochv Gornogo Kryma (Soil atlas of the Mountain Crimea), Kiїv.: Agrarna nauka, 2014. 184 p.

Kostenko I.V., The Impact of Artificial Forest Plantations on Mountain-Meadow Soils of Crimea, Eurasian Soil Science, 2018, Vol. 51, No. 5, pp. 485-494.

Orlov D.S., Sadovnikova L.K., Suhanova N.I., Himija pochv (Soil chemistry), Moscow: Vyssh. shk., 2005. 558 p.

Plugatar’ Ju.V. Lesa (Crimean forests), Simferopol’: IT «ARIAL», 2015, 385 p.

Pochvovedenie (Soil science), Ucheb. dlja un-tov. V.A. Kovda, B.G. Rozanov (eds.). Vol. 2., Moscow: Vyssh. shk., 1988. 368 p.

Polovickij I.Ja., Gusev P.G., Pochvy Kryma i povyshenie ih plodorodija (Crimean soils and increasing their fertility), Simferopol: Tavrija, 1987, 152 p.

Praktikum po agrohimii (Workshop on Agrochemistry), V.G. Mineev (ed.), Moscow: Izd-vo MGU, 2001, 689 p.

Reddy K.J., Wang L., Gloss S.P., Solubility and mobility of copper, zinc and lead in acidic environments, Plant and Soil, 1995, Vol. 171, pp. 53-58.

Ritter E., Vesterdal L., Gundersen P., Changes in soil properties after afforestation of former intensively managed soils with oak and Norway spruce, Plant and Soil, 2003, Vol. 249, pp. 319-330.

Römkens P.F.A.M., Solomon W., Cd, Cu and Zn solubility in arable and forest soils: consequences of land use change for metal mobility and risk assessment, Soil Science, 1998. Vol. 163. No. 11, pp. 859-871.

Sauve S., Murray McBride M., Hendershot W., Soil Solution Speciation of Lead (II): Effects of Organic Matter and pH, Soil Sci. Soc. Am. J., 1998, Vol. 62, pp. 618-621.

Sherene T. Mobility and transport of heavy metals in polluted soil environment, Biological Forum – An International Journal, 2010, Vol. 2. No. 2, pp 112-121.

Tkachenko M.E. Vlijanie otdel’nyh drevesnyh porod na pochvu (The Influence of Individual Tree Species on Soil), Pochvovedenie, 1939, No. 10, pp. 3-16.

Tobratov S.A., Popov V.I., Popova A.V., Faktory i zakonomernosti migracii tjazhelyh metallov v lesnyh geosistemah Rjazanskogo regiona (Factors and patterns of heavy metal migration in forest geosystems of the Ryazan region), Voprosy regional’noj geografii i geojekologii: Materialy regional’noj nauchno-prakticheskoj konferencii: Mezhvuzovskij sbornik nauchnyh trudov, Vypusk 7, Rjazan’: Rjazanskij gosudarstvennyj universitet imeni S.A. Esenina, 2007. pp. 84-114.

Wen-Jie W., Ling Q., Yuan-Gang Z., Dong-Xue S.,Jing A., Hong-Yan W., Guan-Yu Z., Wei S., Xi-Quan C., Changes in soil organic carbon, nitrogen, pH and bulk density with the development of larch (Larix gmelinii) plantations in China, Global Change Biology, 2011, Vol. 17, No. 8, pp 2657-2676.

Reviewer: candidate of Biological Sciences, Senior Researcher Tebenkova D.N.

Original Russian Text © 2020 A.S. Plotnikova, A.O. Kharitonova published in Forest Science Issues Vol. 3, No. 4, pp. 1-10

A.S. Plotnikova*, A.O. Kharitonova

Center for Forest Ecology and Productivity of the RAS,

Profsoyuznaya st. 84/32 bldg. 14, Moscow 117997, Russian Federation

^*E-mail: plotnikova-as-cepl@yandex.ru

Received 04.09.2020

Accepted 17.11.2020

The article is devoted to the description of the web-GIS for mapping fire regimes in the Pechora-Ilych reserve and its environs. The main purpose of the resource is to provide the results of mapping fire regimes in the designated area to a wide range of researchers in an accessible form. Web-GIS allows organizing and storing the received thematic spatial data. The resource performs research and educational functions. The structure of the web-GIS includes the following sections: the study area, fire frequency indicators, fire regimes, fire regime condition class, and fire cycles. The web GIS was created using the ArcGIS StoryMaps tool on the ArcGIS Online platform. All sections use data from the ArcGIS Living Atlas of the World. Web-GIS allows receiving reference information about the indicators of fire frequency, fire cycles and regimes, as well as their deviations within the boundaries of the Pechora-Ilych nature reserve, district forestries, and spatial units. In particular, the results of a retrospective statistical analysis of forest fire indicators within spatial units (fire frequency, mean fire interval, etc.) are available for users.

Key words: web-GIS, fire regime, Pechora-Ilych nature reserve, ArcGIS Online, ArcGIS StoryMaps

At the Center for Forest Ecology and Productivity (CEPF RAS), studies of fire regimes (Barrett et al., 2010) of Russian forests are conducted at all levels – from the national (Plotnikova et al., 2019) to the local (Kharitonova et al., 2019). Local projects include RFBR project No. 17-05-00300 “Development of a methodology for dynamic mapping of fire regimes of forest ecosystems at the local level” (hereinafter referred to as the Project). The Pechora-Ilych Biosphere Reserve and its environs – Kuryinskoye and Yakshinskoye forestry subunits – were chosen as the study area. In the framework of the Project, we developed a method for mapping historical and current fire regimes at the local level. To describe the study area, we generated a number of thematic maps of terrestrial ecosystems based on Landsat satellite data, fire cycles, historical and current fire regimes.

The purpose of this study was to create a web-GIS for providing the results of mapping the fire regimes of the Pechora-Ilych Reserve and its environs to a wide range of researchers in an accessible form. We solved the following tasks: studying the functionality of web-GIS; creating the structure of the system, choosing the optimal composition and content of its sections, determining the means for displaying spatial data; selecting a technological platform for implementing the web-GIS structure.

In the framework of our study we studied the functionality of web-GIS. This is a distributed geoinformation system that consists of two parts – a GIS server and a client (web browser, desktop or mobile application) (Katsko, 2006). Web technology is used to establish communication between the server and the client. Web-GIS has many important features and functions: global coverage and ensuring simultaneous work of many users located anywhere in the world; cross-platform compatibility and a single update mechanism, no fees and no need to purchase specialized software; provision of easy access to the resource for non-specialists; publicly available spatial basis; data scaling option (Shokin, Potapov, 2015; Alekseenko et al., 2019).

A detailed analysis of Russian scientific and educational geoportals of protected areas is given in the article (Alekseenko et al., 2019). Authors divided interstate, national, and regional network resources with data on protected areas into three groups: inventory, multipurpose, and own geoportals. Also they considered the cases of using web-GIS in the following reserves: the Taimyrsky, the Dagestansky, the Stolby, and the Belogorye. The analysis showed that most of the Russian web-GISs use open source software. The commercial platforms use Esri and GeoMixer products. In terms of functionality, only visualization of spatial data is usually implemented. There is a lack of digital and cartographic information.

The provision of free or differentiated access to the reserve’s web-GIS is determined by the goals of its creation. Publicly accessible geoportals (i.e., the Dagestan and Pechora-Ilych reserves) are developed for tourists, students of specialized universities, employees of scientific organizations, and specialists in the field of environmental protection. Access can be restricted, in particular, when developing a system for combining the scientific work of employees of different profiles of one reserve on an Internet platform (Alekseenko, Samoletova, 2017). An example of differentiated access is the web-GIS of the Belogorye reserve (http://belogorie.maps.arcgis.com/home/index.html).

The indicated lack of digital data is noted in the Pechora-Ilych Reserve’s web-GIS, which was created by the NextGIS company (http://pechora-reserve.nextgis.com/resource/108 /display?panel=layers). It presents a set of layers: border of the protected areas (border of the reserve and the buffer zone), zoning of the protected areas (forest districs of the reserve), infrastructure, topography (isohypses, swamps, hydrography), ecological routes and attractions (ecological routes, weathering pillars of Man-Pupunyor, photographs). Thus, at present, web-GIS lacks thematic spatial data. The user has access to the functions of scaling, measuring distance, and area on the map, and the vertical shutter tool. The OpenStreetMap resource is used as a cartographic basis (https://www.openstreetmap.org).

Among the publicly available web-GIS reserves, we note the developments of the Data East company. The company has created interactive maps to provide travelers with the necessary information about recreation sites, transport infrastructure, hydrography, tourist routes, and natural attractions (https://carrymap.com/ru/gallery/maps-for-outdoor-activity/). In Russia, digital maps were generated for reserves such as the Russian Arctic National Park in the Arkhangelsk Region, the Kuril Nature Reserve in the Sakhalin Region, the Kandalaksha Nature Reserve in the Murmansk Region, and others. In the USA, maps were generated for the Glacier, Sequoia, and Zion National Parks. Resources are accessed via the free CarryMap app (https://carrymap.com/en/support/ carrymap-for-windows/), which allows using them without an internet connection.

For example, the map of the Kuril Nature Reserve includes the marks of the main attractions and infrastructure (parking lots for tourists, ports, shops, pharmacies, hospitals, and post offices) and descriptions of natural objects (capes, bays, mountain peaks, and notches) (https://carrymap.com/ru/gallery/mapgallerylibrary/maps-for-outdoor-activities/kurils-nature-reserve-kunashir-island/). To create the basemap, we used an up-to-date topographic map at a scale of 1:100,000.

Analysis of the web-GIS’s functions and examples of their implementation showed that it is feasible to use this technology to achieve the goal set in the study.

MATERIAL AND METHODS

As noted above, the choice of the type of web-GIS is largely determined by the goals of its creation. Web-GIS of fire regimes should perform research and educational functions. It is also designed to solve problems such as notification of the scientific community about new results in the study area, systematization and storage of the received thematic spatial data, and viewing materials by non-GIS specialists.

When creating a web-GIS structure, the main criteria were the simplicity and clarity of the resource for the user as well as the provision of him/her with the necessary information content. The composition and content of the system’s sections should be sufficient to determine the fire regimes in the study area, spatial study of the most important fire indicators, and natural conditions. In addition, the system should provide the ability to assess the deviations of fire regimes from their historical values. Deviations lead to the transformation of key components of ecosystems and changes in the frequency and severity of fires. It requires a section that would contain one of the important characteristics of the fire regime – the fire cycle, which estimates the time required to burn out forest area equal to the area of the spatial unit of damage analysis (Frech et al., 1999). Thus, the web-GIS includes the following sections: study area, fire indicators, fire regimes, fire regime condition class, fire cycles (Fig. 1).

Figure 1. The web-GIS structure of fire regimes of the Pechora-Ilych nature reserve and its environs

The Study Area section contains data obtained in the study of the physical and geographical conditions and vegetation cover of the region under study (Gavrilyuk et al., 2018). The section contains cartographic layers with the boundaries: Pechora-Ilych nature reserve, Kurinsky and Yakshinsky district forestries, river basins, and spatial units. The interactive use of the map suggests the use of a “pop-up window”, which allows obtaining numerical and graphical information about the ratio of vegetation cover classes in the total area of ​​a spatial unit.

The Fire Indicators section presents statistical data on the number and average area of ​​fires, the share of the area covered by fire within the boundaries of spatial units. The “pop-up window” also provides information on the fire indicators within the boundaries of the reserve and forestry areas, indicating the data source (aviation, historical). The results of mapping historical and current fire regimes are reflected in the Fire Regimes section. Interactive work with the map allows receiving information about the type of fire regime for each spatial unit. For the reserve and forestry, information is provided on the ratio of areas of different classes of fire regimes. The section Fire Regime Condition Class is included in the web-GIS to represent the classes of the state of the fire regime. The Fire Cycles section contains maps of fire cycles for the main part of the Pechora-Ilych Reserve for four time periods: 1850–1899, 1900–1951, 1952–1999, and 2000–2014. Additional indicators used in calculating cycles include area covered by fire, forest area, and study period.

According to the work of N.A. Alekseenko (2014) when creating a geoportal for any reserve, it is advisable to use a map of natural boundaries to combine various information. Thus, all the sections of the web-GIS of fire regimes contain a map of spatial units based on the boundaries of river basins (Plotnikova, Kharitonova, 2018). Mapping of fire regimes and cycles was conducted within the boundaries of spatial units; we collected statistical information on groups of tree species, class of fire regime, and fire indicators.

When choosing a technological platform for implementing the structure of web-GIS fire regimes we took into account the need to develop a simple, intuitive, and convenient interface. This requirement is preconditioned by the wide target audience of the system, which do not necessarily have the skills to work with spatial data in professional geographic information systems. During the study, we considered modern technological platforms such as GeoMixer, MapBox, Mangomap, Azimap, and ArcGIS Online. In addition to ease of use and free access, the possibility of publishing spatial data on a basic interactive map was taken into account.

GeoMixer is a web-based geoinformation platform used to solve a wide range of tasks for visualization, analysis, organization, and data integration (http://geomixer.ru). To create a web-GIS on the GeoMixer platform, it is necessary to pre-install a number of software components – Microsoft IIS web server, Microsoft.NET Framework, PostgreSQL DBMS, or MS SQL Server. In addition, there are requirements for minimum recommended hardware configuration including restrictions on bit capacity of a multi-core processor, size of the RAM and redundant array of independent disks (RAID). Unlike GeoMixer, MapBox (https://www.mapbox.com), Mangomap (https://mangomap.com), and Azimap (https://www.azimap.com) platforms allow generating interactive web maps without installing additional software. The platforms include the functions of visualization and analysis of spatial data, generation and thematic design of web maps. Open Street Map data is used as a cartographic basis.

ESRI’s ArcGIS Online platform is one of the world leaders in geographic information systems (https://www.esri-cis.ru/). It allows creating, storing, and managing web maps, applications, and other spatial data. The platform was chosen to create a web-GIS of fire regimes because it allows for free creation of a cartographic resource for the research project. In addition, ArcGIS Online allows using data and maps from the ArcGIS Living Atlas of the World. It is the most complete collection of global geographic information available today (base maps, satellite images, statistical information, etc.).

RESULTS AND DISCUSSION

Our web-GIS of fire regimes (http://cepl.rssi.ru/fire-regime-pechora-reserve/) allows visualizing and analyzing the spatial data created within the framework of the Project without the use of specialized professional full-featured geographic information systems. Thus, the resource provides the obtained cartographic results in a form accessible to a wide range of researchers (Fig. 2).

Figure 2. The Web-GIS interface of the study area fire regimes

Using the ArcGIS StoryMaps tool on the ArcGIS Online platform, we generated interactive thematic maps showing study area, fire indicators, fire regimes, fire regime condition class, and fire cycles (Fig. 3). The ArcGIS Living Atlas of the World (https://livingatlas.arcgis.com/en/home/) was used as a cartographic basis for visualizing the spatial data of the Project. It is a collection of shape maps, geodata layers, images, and applications. In addition, the Living Atlas provides a regularly updated public basemap of high and ultrahigh resolution space images for the territory of Russia. We have chosen a base containing hydrographic objects, settlements, relief, and administrative boundaries of the constituent entities of the Russian Federation for all interactive maps.

Web-GIS allows to obtain the reference (attributive) information about fire indicators, fire cycles, and regimes, as well as fire regime condition class within the boundaries of the Pechora-Ilych nature reserve, district forestries, and spatial units. In particular, we dispose of the results of a retrospective statistical analysis of fire indicators within spatial units (fire frequency, mean fire interval, and others).

Research in the territory of the Pechora-Ilych Reserve is conducted in various scientific areas (Smirnova et al. 2011; Shevchenko, 2015; Geraskina, 2016; et al.). However, it is difficult to find works that graphically represent the obtained spatial results with the possibility of interactive access. Thanks to this study, the results of mapping the fire regimes of the reserve and its environs became available to a wide range of specialists.

a)	b)
с)	d)

Figure 3. The web-GIS sections: a) burnability indicators, b) fire cycles, c) fire regimes, d) fire regime condition class

CONCLUSION

The study resulted in designing a web-GIS of fire regimes in the Pechora-Ilych reserve and its environs. Thanks to our resource, various characteristics of the fire regimes of the study area are available to a wide range of researchers involved in geoecology, forest management, climatology, pyrology, and related scientific fields.

We indicated the functions performed by the web-GIS and the tasks to be solved. We determined the structure of the web-GIS and developed the composition and content of the system sections. We substantiated the choice of a technological platform for the implementation of a geographic information system in the Internet.

ACKNOWLEDGEMENTS

The study was conducted with the financial support of the Russian Foundation for Basic Research (project No. 17-05-00300) and within the framework of the state assignment AAAA-A18-118052400130-7 “Methodological approaches to assessing the structural organization and functioning of forest ecosystems”.

REFERENCES

Agee J.K., Fire ecology of Pacific Northwest forests, Island Press: Washington, DC, 1993, p. 493.

Alekseenko N.A., Edinaja baza dannyh OOPT Rossii (Unified database of protected areas of Russia), Proc. 15th International Scientific Conference “Conservation of Biodiversity of Kamchatka and Coastal Waters”, Petropavlovsk-Kamchatsky, 17-18 November 2014, Petropavlovsk-Kamchatsky: Kamchatpress, pp. 113-117.

Alekseenko N.A., Koshkarev A.V., Kuramagomedov B.M., Medvedev A.A., Geoportaly rossijskih osobo ohranjaemyh prirodnyh territorij (Geoportals of Russian Specially Protected Natural Areas), Geodezija i kartografija, 2019, Vol. 80, no.5, pp. 34-46.

Alekseenko N.A., Samoletova M.I., Predlozhenija po sozdaniju geoportala dlja obespechenija nauchnoj raboty zapovednika «Belogor’e» (Proposals for the creation of a geoportal to support the scientific work of the «Belogorye» reserve), Proc. 7th International Scientific Conference «Problems in Nature Management and the Ecological Situation of European Russia and Adjacent Countries» (in Memory of Prof. A. Petin), Belgorod, 24-26 October 2017, Belgorod: Politerra, pp. 379-384.

Barrett S.W., Havlina D., Jones J., Hann W., Frame C., Hamilton D., Schon K., Demeo T., Hutter L., Menakis J., Interagency Fire Regime Condition Class Guidebook. Version 3.0., 2010, available at: https://www.landfire.gov/frcc/frcc_guidebooks.php (August 12, 2020).

Frech R.J., Caputo J.A., McCulloch K., Forest fire cycle analysis for applications in forest management planning. Ontario Ministry of Natural Resources AFFM Publication. 1999. No. 362.1999.

Gavriljuk E.A., Plotnikova A.S., Plotnikov D.E. Kartografirovanie nazemnyh jekosistem Pechoro-Ilychskogo zapovednika i ego okrestnostej na osnove vosstanovlennyh mul’tivremennyh sputnikovyh dannyh multirial-Landsat based the reconciliation of the dannyh Landsat satellite data), Sovremennye problemy distancionnogo zondirovanija Zemli iz kosmosa, 2018, Vol. 15, No.5, pp. 141-153.

Geraskina A.P. The population of earthworms (Lumbricidae) in the main types of dark coniferous forests in Pechora-Ilych Nature Reserve, Biology Bulletin, 2016, Vol. 43, No. 8, pp. 819-830.

Haritonova A.O., Plotnikova A.S., Ershov D.V., Sovremennye i istoricheskie pozharnye rezhimy Pechoro-Ilychskogo zapovednika i ego okrestnostej (Current and historical fire regimes of Pechora-Ilych nature reserve and its surroundings), Voprosy lesnoj nauki, Vol. 2, No. 3, pp. 1-17.

Kacko S. Ju., Klassifikacija i principy raboty geoinformacionnyh WEB-serverov v internet-sisteme “Klient-Server” (Classification and principles of operation of geoinformation WEB-servers in the Internet system “Client-Server”), Geo-Sibir, 2006, Vol. 1, No.1, pp. 211-215.

Plotnikova A.S., Ershov D.V., Haritonova A.O., Shuljak P.P., Bartalev S.A., Stycenko F.V., Prostranstvennaja ocenka sovremennyh pozharnyh rezhimov lesnyh jekosistem Rossii (Spatial assessment of modern fire regimes of forest ecosystems in Russia), Sovremenyye problemy distancinnogo zondirovaniya Zemli iz kosmosa, 2019, Vol. 16, No. 5, pp. 228-240

Plotnikova A.S., Haritonova A.O., Vydelenie granic vodosbornyh bassejnov rek na lokal’nom prostranstvennom urovne (The identification of drainage basins borders at local spatial level), Voprosy lesnoj nauki, 2018, Vol. 1, No.1, pp. 1-10.

Shevchenko N.E., Soobshchestva sosnovo-elovykh lesov verkhnei chasti basseina r. Pechory (Pechoro-Ilychskii biosfernyi zapovednik, Sobinskii uchastok) (Communities of pine-spruce forests in the biopart of the Pechora site-Ilybinsky river basin (Pechora-Ilychsky Biosphere Reserve, Sobinsky site)), Lesotekhnicheskii zhurnal, 2015, Vol. 5, No. 3 (19), pp. 142-152.

Smirnova O.V., Aleinikov A.A., Semikolennykh A.A., Bovkunov A.D., Zaprudina M.V., Smirnov N.S., Prostranstvennaya neodnorodnost ‘pochvenno-rastitel’nogo pokrova temnohvojnyh lesov v Pechoro-Ilychskom zapovednike (Spatial heterogeneity of the soil-plant cover in dark coniferous forests of the Pechoro-Ilychskii Reserve), Lesovedenie, 2011, No. 6.pp. 67-78.

Shokin Ju.I., Potapov V.P., GIS segodnja: sostojanie, perspektivy, reshenija (GIS today: current state, perspectives, solutions), Vychislitel’nye tehnologii, 2015, Vol. 20, No. 5, pp. 175-213.

Reviewer: Ph.D. in biology, Director of the Center for Forest Pyrology R.V. Kotelnikov

Original Russian Text © 2020 A.P. Geraskina published in Forest Science Issues Vol. 3, No. 3, pp. 1-20 

A.P. Geraskina

Center for Forest Ecology and Productivity of the Russian Academy of Sciences

Profsoyuznaya st. 84/32 bldg. 14, Moscow, 117997, Russia

^*Email: angersgma@gmail.com

Received 25.05.2020

Accepted 24.06. 2020

To date, forest ecology has not made any clear conclusions regarding the impact of large saprophagous invertebrates such as earthworms on soil carbon dynamics. Some authors claim that earthworm activities result in decreased carbon accumulation. Other studies show that earthworms contribute to soil carbon accumulation. At the same time, many studies do not take into account the differences between trophic and digging activity of different morpho-ecological groups of earthworms in different soil horizons. The objective of this study was to carry out differentiated assessment of the impact of different morpho-ecological groups of earthworms on carbon accumulation and correspondent soil parameters (nitrogen content and С/N ratio) throughout the change in forest succession status. Field operations were performed in the spring and summer of 2016 and 2018 in three regions: Bryansk Oblast (Bryansk Forest reserve), Moscow Oblast (Moskva–Oka plain, Valuyevsky urban forest) and Northwest Caucasus (Krasnodar Krai, Apsheron forestry; Republic of Adygeya, Caucasian Biosphere Reserve). Three main stages of coniferous-broadleaf forest restoration after clear cuttings were identified in each region. Three test plots 50х50 m were allocated for each stage; geobotanical and soil descriptions as well as earthworm registration were carried out on each plot. It was found out that during the change in forest succession status the species composition and the set of morpho-ecological groups of earthworms became more complicated, but there was no successive replacement of any groups with others. Ambiguous effects of different morpho-ecological groups of earthworms on carbon accumulation in forest soils were revealed. Negative correlation was found between the total biomass of earthworms feeding on the soil surface (epigeic, epi-endogeic and anecic species) and litter store. In the humus horizon, the biomass of epi-endogeic species was positively correlated with the content of carbon. C/N ratio and nitrogen content are unidirectionally correlated with the biomass of earthworms in the horizons of their activity: with an increase in the biomass of earthworms of different morpho-ecological groups, the C/N ratio decreases, and the nitrogen content increases.

Key words: forest type, succession status, chronoseries, litter, nitrogen, C/N ratio, saprophagous invertebrates, biomass

Productivity of forest ecosystems is largely determined by the activity of soil saprophages, since the bulk of energy flows through the detrital food chain (Striganova, 2012). The flow intensity of dead organic matter entering the soil is at least 95% of the total amount of organic matter assimilated by producers (Begon et al., 1986). In the mixed and broadleaf forests of the European part of Russia, the main agents contributing to plant litter decomposition are large saprophages, up to 90% of their biomass consisting of earthworms (Abaturov, 1976; Striganova, 1980).

On the one hand, plant litter (composed of leaves, stems, and roots) and plant root secretions serve as a source of carbon for earthworms (Goncharov, 2014; Gleixner, 2013). On the other hand, earthworms provide carbon fixation in the soil in two main ways: by means of humus formation as a result of their trophic activity and by means of carbon transfer from the soil surface to lower horizons during their active burrowing. In the absence of earthworms and other large saprophages, the destruction of plant litter is carried out by microorganisms and saprotrophic meso- and microfauna not capable of transferring carbon to the mineral horizons of soils. Moreover, during the microbial respiration, carbon dioxide is released, which leads to carbon loss rather than its fixation in the soil (Frouz et al., 2013).

Recent studies of global carbon dynamics in terrestrial ecosystems provide ambiguous estimates of the impact of earthworms on carbon accumulation in the soil. Some authors claim that earthworm activity results in reduced carbon accumulation (Alban, Berry, 1994; Burtelow et al., 1998; Bohlen et al., 2004). Other studies show that earthworms contribute to soil carbon accumulation (Pulleman et al., 2005; Novara et al., 2015). Probably, these conflicting conclusions are attributed to the fact that most studies consider the complex of earthworms as a whole, taking into account the total biomass of all earthworm species. This does not factor in any differences between individual morpho-ecological groups of earthworms, where in relation to the organic matter of the soil, primary humus-forming species are distinguished, i.e. species feeding on the surface (epigeic, epi-endogeic and anecic), as well as secondary humus-forming species feeding in the soil (endogeic) (Perel’, 1979).

The objective of this study was to make a differentiated assessment of the impact of earthworms of different morpho-ecological groups on carbon accumulation in forest soils during the change in forest succession status.

            Tasks:

1. To study the species composition, biomass and dynamics of morpho-ecological groups of earthworms during the transformation of forest communities.
2. To analyze the impact of earthworms of 4 morpho-ecological groups on litter stores and carbon content in soil horizons.
3. To evaluate the impact of earthworms of different morpho-ecological groups on the C/N ratio and nitrogen content as the most significant soil indicators associated with carbon accumulation processes that are regulated by earthworms.

MATERIALS AND METHODS

Field work was carried out in the spring and summer of 2016 and 2018 in coniferous-broadleaf forests of three regions of the European part of Russia: Bryansk Woodlands (territory of the Bryansk Forest reserve – 52.5464 N, 34.0797 E), Moskva–Oka plain (Valuyevsky urban forest – 55.5780 N, 37.3272 E), and the Northwest Caucasus (Apsheron forestry, Otdalenny village, Krasnodar Krai – 44.0669 N, 39.7164 E, and the Guzeripl cordon of the Caucasian biosphere reserve, Republic of Adygeya – 44.0002 N, 40.1421 E). Three types of forest, which represent different stages of the succession change of plant communities (chronoseries) after clear cuttings, have been examined in each region (Lukina et al., 2018).

In Bryansk Forest reserve, the following forests were studied: pine forests (aged 40–60 years), pine-broadleaf forests (aged 70–120 years), and broadleaf-spruce forests (older than 120 years). Soil type: sod-podzolic ferrous illuvial sandy soils on fluvioglacial sands (Klassifikacija pochv…, 2004), or Podzols Albic (WRB, 2015). The clay-silt fraction in the soil-forming rocks ranges from 0.5 to 5%. Active acidity of the soil-forming rocks: pH 5.1–5.7 (Lukina et al., 2018).

On the territory of the Moskva–Oka plain, the following forests were studied: birch-linden forests with aspen (aged 50–70 years), linden forests with birch and aspen (aged 90–110 years), and broadleaf-spruce forests (aged 115–125 years). The soil is sod-podzolic middle loamy on covering loam with underlying moraine (Klassifikacija pochv…, 2004), or Retisols Albic (WRB, 2015). The clay-silt fraction in the soil-forming rocks ranges from 34.3 to 45.3%. Active acidity of the soil-forming rocks: pH 5.1–5.6 (Lukina et al., 2018).

On the territory of the Northwest Caucasus, the following forests were studied: aspen-hornbeam forests (aged 45–65 years), fir-beech-hornbeam forests (aged 80–110 years), fir-beech forests (older than 400 years). Soil type: heavy loamy brown soil on clay shales (Klassifikacija pochv…, 2004), or Cambisols Dystric (WRB, 2015). The clay-silt fraction in the soil-forming rocks ranges from 36.5 to 72.7%. Active acidity of the soil-forming rocks: pH 5.5–5.7 (Lukina et al., 2018).

Three trial plots (TPs) of 50×50 m (27 in total), where geobotanical, soil descriptions and earthworm registration were performed, were selected for each type of forest in three regions (Geras’kina, 2018; Lukina et al., 2018; Kuznecova et al., 2019; Shevchenko et al., 2019).

Earthworms were registered by excavation of soil with hand sorting of samples: at each TP, from 10 (Bryansk Woodlands, Moskva-Oka plain) to 16 samples (Northwest Caucasus) with an area of 25×25 cm² and a depth of 30 cm were taken. In total, 90 soil samples were taken in the forests of the Bryansk Forest reserve, 60 – in the forests of the Moskva-Oka plain, and 144 – in the forests of the Northwest Caucasus. Earthworms were fixed in 96% ethyl alcohol. Species were identified using the key-book by T.S. Vsevolodova-Perel’ (1997). Morpho-ecological groups of earthworms were classified according to T.S. Perel’ (1979). The biomass was determined by weighing fixed earthworms with a full intestine.

At each TP, reference soil pits were made under the forest canopy, from which litter (L subhorizon) and soil (every 10 cm) were sampled down to the soil-forming rock. In all samples, pH of the water extract was measured using potentiometric analysis. The carbon and nitrogen content was evaluated in the ecoanalytic laboratory of the Chromatography Research Equipment Sharing Centre of the Komi Biology Institute, Scientific Centre of the Ural Branch of the Russian Academy of Sciences, using a CHN analyzer EA 1110 (CHNS-O). Litter samples of 0.25×0.25 m were taken at each TP in three replications to determine the mass of the litter and its carbon reserves. Carbon stocks in the litter and soil mineral horizons were calculated according to the procedural guidelines (Metodicheskie ukazanija…, 2017). Calculations were carried out taking into account the actual thickness of horizons as well as for fixed layers of 0–30, 0–50, and 0–100 cm (Lukina et al., 2018; Kuznecova et al., 2019). Soil horizons: litter or organogenic horizon (O), humus or humus-accumulative horizon (A), eluvial horizon (E), illuvial horizon (B), parent rock (C) were classified according to the National Atlas of Soils of the Russian Federation (2011).

Statistical processing of data on earthworms was performed using the MS Excel 2019 and Statistica 6.0 software packages. To detect statistically significant differences, the nonparametric Kruskal-Wallis test was used, the significance level (p) was set equal to ≤ 0.05. Since the values of the biomass of earthworms of different morpho-ecological groups varied greatly, further analysis of their correlation with carbon accumulation in different soil horizons (and the associated indicators, i.e. content of N and the C/N ratio) included only the morpho-ecological groups of earthworms, where the variation of biomass in the samples showed normal distribution. Based on the values of the Pearson’s test (K obs. < K crit.; K crit. = 12.591), normal distribution was shown by the data sets of biomass of epigeic earthworms in the forests of the Bryansk Woodlands and the Moskva–Oka plain, epi-endogeic earthworms – in the forests of the Moskva–Oka plain, endogeic earthworms – in the forests of the Northwest Caucasus and the Moskva–Oka plain, as well as the total biomass of earthworms of morpho-ecological groups feeding on the soil surface (epigeic, epi-endogeic and anecic) in the forests of the Northwest Caucasus and the Moskva–Oka plain. These data series were used for linear regression analysis (coefficient of determination R²) in order to identify correlations between groups of earthworms and soil parameters. Activity horizons of different morpho-ecological groups of earthworms that are significantly influenced by earthworms were taken into account. Epigeic, epi-endogeic and anecic species are active in the litter horizon, and epi-endogeic and endogeic species are active in the humus horizon.

RESULTS AND DISCUSSION

1. Species diversity and changes in the composition of morpho-ecological groups of earthworms during post-cutting forest successions

1.1 Forests of the «Bryansk Forest» reserve

4 species of earthworms of two morpho-ecological groups were found: epigeic Dendrodrilus rubidus tenuis (Eisen, 1874), Dendrobaena octaedra (Savigny, 1826); epi-endogeic Lumbricus rubellus Hoffmeister, 1843, and Eisenia nordenskioldi (Eisen, 1879) (Table 1). In total, at least ten common species were found in the zone of coniferous-broadleaf forests (Perel’, 1979). Poor species composition in the studied forests is primarily due to the light granulometric composition of the soils of this territory – in all three types of forest, the soils are sandy loam (Lukina et al., 2018; Kuznecova et al., 2019). Light sandy loam soils with weak moisture-retention capacity are known to be an unfavorable habitat for earthworms (Zhukov, 2004; Curry, 2004, etc.).

Table 1. Species composition and numbers of earthworms of different morpho-ecological groups found in coniferous-broadleaf forests of the studied regions

Explanatory notes:

В1: pine forests,

B2: pine-broadleaf forests,

B3: broadleaf-spruce forests,

M1: birch-linden forests with aspen,

M2: linden forests with birch and aspen,

M3: spruce-broadleaf forests,

С1: aspen-hornbeam forests,

С2: fir-beech-hornbeam forests,

С3: fir-beech forests

In pine forests (B1), no earthworms were found in soil samples. Moreover, no earthworms were found in these forests during the observation of favorable habitats either, i.e. degradations, pits, deadwood of late stages of decomposition. The absence of earthworms in these forests is not only due to the light granulometric composition of the soil, but also due to the litter quality. The litter is dominated by difficultly decomposed fractions (pine) and ground cover (bilberry, cowberry, heather). Litter acidity ranges from 4.3 to 4.7, which is also unfavorable for earthworms. The optimal pH for the active life, including reproduction, of most earthworm species ranges from 5.5 to values close to neutral (Perel’, 1979; Hirth et al., 2009; Moore et al., 2013).

Figure 1. Dynamics of the biomass of morpho-ecological groups of earthworms during changes in the succession status of forests
Note. I – Bryansk Woodlands, II – Moskva–Oka plain, III – Northwest Caucasus. For designation of forest types B1…C3 see Table 1.

In pine-broadleaf forests (B2), three earthworm species were found: epigeic D. octaedra and D. r. tenuis as well as epi-endogeic E. nordenskioldi. The number and biomass of earthworms are low (Table 1, Fig. 1), but their life in these forests, in contrast to pine forests, is possible due to the presence of high-quality litter provided by undergrowth (linden, maple) and shrubs (buckthorn, hazel). Also, the litter in these forests is more favorable for earthworms due to increased pH values up to 5.5–5.9, as compared to the previous stage of succession.

In broadleaf-spruce forests (B3), three species of Lumbricidae were found: epigeic D. octaedra, D. r. tenuis, and epi-endogeic L. rubellus. The number and biomass of earthworms, as in complex pine forests, is low (Table 1, Fig. 1), despite the increased proportion of high-quality litter provided by the tree layer (linden, maple, ash), undergrowth (linden, maple, elm), and shrubs (hazel, bird cherry). Litter acidity in these forests is within optimal values: pH is 5.9–6.4, which is not a limiting factor for earthworm activity.

Statistically significant differences in the biomass of epigeic and epi-endogeic earthworm species were found between pine-broadleaf forests (B2) and broadleaf-spruce forests (B3), and there were also differences in the total biomass of earthworms at three stages of succession (Fig. 1, Table 2).

Table 2. Values of the Kruskal-Wallis H-test when comparing the biomass of earthworms of different morpho-ecological groups in different forest types

Morpho-ecological group	Compared forest types	df	Нu	Р
Epigeic	*B2 х B3	1	2.167	0.041**
	M2 х M3	1	0.079	0.777
	C1 х С2 х С3	2	0.492	0.781
Epi-endogeic	B2 x B3	1	1.750	0.048**
	M2 x M2 x M3	2	4.610	0.036**
	C1 x C3	1	0.437	0.508
Endogeic	M2 x M2 x M3	2	8.564	0.014**
	C1 х С2 х С3	2	0.862	0.649
Anecic	M2 х M3	1	0.784	0.375
	C2 x C3	1	4.419	0.012**
All groups	B1 x B2 x B3	2	6.882	0.032**
	M2 x M2 x M3	2	0.929	0.629
	C1 х С2 х С3	2	0.965	0.617

Note: *For designation of forest types B1…C3, see Table 1.

 ** The differences are statistically significant (p≤0.05).

Thus, with changing plant communities and the litter quality becoming more favorable for earthworms, epigeic and epi-endogeic species show themselves in the soils of light granulometric composition of the Bryansk Woodlands. Nevertheless, the number of earthworms remains numerically insignificant, and they do not play any significant functional role in litter decomposition (Lukina et al., 2018).

1.2 Forests of the Moskva–Oka plain

9 species of earthworms belonging to 4 morpho-ecological groups were found: epigeic D. r. tenuis, D. octaedra, Lumbricus castaneus (Savigny, 1826); epi-endogeic L. rubellus, endogeic Aporrectodea caliginosa caliginosa (Savigny, 1826), Aporrectodea rosea (Savigny, 1826), Octolasium lacteum (Oerley, 1885), and anecic Lumbricus terrestris Linnaeus, 1758, Aporrectodea longa (Ude, 1885). Factors favorable for earthworm vital activity in these forests are the granulometric composition of soils (middle loamy), the presence of high-quality litter from trees and shrubs, as well as the optimal litter acidity (5.8–6.1) at all stages of succession.

In birch-linden forests with aspen (M1), 4 species of earthworms were found: the epi-endogeic L. rubellus as well as endogeic A. с. caliginosa, A. rosea, and O. lacteum. Endogeic species make the largest contribution to the biomass (Fig. 1). The absence of epigeic species is probably due to the rapid utilization of high-quality litter of linden and birch by soil biota (Berezina, 2016).

In linden forests with birch and aspen (M2), 7 species of earthworms were identified: epigeic D. octaedra, L. castaneus, epi-endogeic L. rubellus, endogeic A. с. caliginosa, A. rosea, and anecic L. terrestris, A. longa (Table 1). Despite the presence of 4 morpho-ecological groups of Lumbricidae, the biomass of endogeic species exceeds the biomass of earthworms of other groups (Fig. 1).

In broadleaf spruce forests (M3), 8 species of earthworms were identified: epigeic D. octaedra, D. r. tenuis, L. castaneus, epi-endogeic L. rubellus, endogeic A. caliginosa, A. rosea, and anecic L. terrestris, A. longa. The difference between the spruce-broadleaf forest and the two previous stages of the chronoseries is a significant decrease in the biomass of endogeic species and the 4.5-fold increase in the biomass of the epi-endogeic L. rubellus.

Thus, in the middle loamy soils of the Moskva–Oka plain, the completed complex of earthworms is only found in the oldest forests (older than 110 years). Despite the presence of rapidly decomposing broadleaf litter (from linden, birch), only two morpho-ecological groups of earthworms are active in these forests at the initial stages of succession, i.e. endogeic and epi-endogeic. With increasing age of forest communities and increasing proportion of slowly decomposing litter (spruce) in the litter horizon, the conditions for epigeic, epi-endogeic and anecic species that feed on leaf litter of trees, shrubs and herbs on the soil surface remain favorable (Perel’, 1979; Hoeffner et al., 2018; Huang et al., 2020).

1.3 Forests of the Northwest Caucasus

8 species of earthworms belonging to 4 morpho-ecological groups were found: epigeic D. r. tenuis, D. octaedra, Dendrobaena attemsi Michaelsen, 1902; epi-endogeic Eisenia fetida (Savigny, 1826), endogeic Dendrobaena schmidti schmidti (Michaelsen, 1907), Dendrobaena tellermanica Perel’, 1966, Aporrectodea jassyensis (Michaelsen, 1891), and anecic Dendrobaena mariupolienis Wyssotzky, 1898.

7 species of earthworms were found in aspen-hornbeam forests (C1): epigeic D. octaedra, D. attemsi; epi-endogeic E. fetida; endogeic D. s. schmidti, D. tellermanica, A. jassyensis, and anecic D. mariupolienis (Table 1). The biomass of endogeic species is significantly higher than that of other groups (Fig. 1).

5 species of earthworms were found in fir-beech-hornbeam forests (C2): epigeic D. octaedra, D. attemsi; endogeic D. s. schmidti, A. jassyensis, and anecic D. mariupolienis.

In the oldest fir-beech forests (C3), that are older than 400 years, 7 species of earthworms were identified: epigeic D. octaedra, D. attemsi, D. r. tenuis; epi-endogeic E. fetida; endogeic D.s. schmidti, A. jassyensis, and anecic D. mariupolienis. An important feature of the earthworm population at the terminal stage of succession of coniferous-broadleaf forests of the Northwest Caucasus is a 4–9-fold increase in the biomass of anecic earthworms as compared to the previous stages of the chronological order (Geraskina, 2018), the differences are statistically significant (Fig. 1, Table 2).

In general, 4 morpho-ecological groups of earthworms were present in the chronoseries of the forests of the Northwest Caucasus already at the initial stages, which is due to favorable forest brown soils and the presence of mixed litter, which is better for earthworms in trophic and topical terms (Sariyildiz, 2008; Sariyildiz, Küçük, 2008). Litter acidity at all stages of succession is close to optimal values (pH 5.1–6.0) and does not limit the activity of earthworms. As in the forests of the Moskva–Oka plain, increasing biomass of anecic earthworms was observed in the Northwest Caucasus in the process of succession.

Thus, the example of three types of forest study objects in different regions showed that the set of morpho-ecological groups of earthworms is determined by the soil granulometric composition and litter quality of the tree layer, undergrowth and shrubs. At the initial stages of post-cutting forest restoration, the composition of morpho-ecological groups of earthworms is incomplete (with the exception of the forests of the Northwest Caucasus). With changing succession status of forests, the set of morpho-ecological groups of earthworms becomes more complex, but there is no successive replacement of one group by others.

2. Impact of earthworms of different morpho-ecological groups on carbon accumulation in forest soils and associated soil parameters, such as litter store, nitrogen content, and C/N ratio

Litter thickness relies on the activity of earthworms (Vsevolodova-Perel’ et al., 1995; Suarez et al., 2006; Holdsworth et al., 2012; Huang et al., 2020, etc.). Correlation analysis showed that in all regions, the stock of the L subhorizon is negatively related to the biomass of earthworms active in the litter horizon. The highest values of the coefficient of determination (R² = 0.65) were obtained for the forests of the Bryansk Woodlands, where the store of L subhorizon is at least twice as high as compared to the forests of the Moskva–Oka plain and the Northwest Caucasus (with the exception of plots of old-aged fir-beech forests) (Fig. 2). Litter accumulation in the forests of the Bryansk Woodlands corresponds to a very low biomass of earthworms (Fig. 1). As our studies have shown, the biomass of other groups of saprophagous invertebrates is also small here. Litter store in the forests of the Moskva–Oka plain is probably more actively controlled by the activity of the epi-endogeic L. rubellus, since its contribution to the total biomass of earthworms is significantly higher in most forest communities than the contribution of epigeic and anecic species (Fig. 1).

Figure 2. Dependence of the stock of litter L subhorizon on the biomass of epigeic, epi-endogeic and anecic earthworm species

In the forests of the Northwest Caucasus, among the groups of earthworms that regulate litter stores, anecic species make the greatest contribution due to their significantly higher biomass than that of epigeic and epi-endogeic species (Fig. 1).

A significant negative correlation was found between the biomass of epi-endogeic earthworms and the C/N ratio in the litter and in the humus horizon (the example of the forests of the Moskva–Oka plain, where the highest biomass of L. rubellus was found (Fig. 3a, 4a)). And on the contrary, the biomass of epi-endogeic L. rubellus is positively related to the nitrogen content in the litter and the humus horizon (Fig. 3b, 4b). At the same time, the direction of correlation with the organic carbon content differs: a negative correlation of carbon content with the biomass of epi-endogeic earthworms is shown in the litter L subhorizon (Fig. 3c), whereas in the humus horizon, on the contrary, there is a positive correlation (Fig. 4c). Since epi-endogeic earthworms actively feed on the soil surface, which can lead to a decrease in the organic carbon content in the litter, but at the same time they belong to the primary humus-forming agents (Perel’, 1979), it is most likely that the effect of organic matter accumulation during humus formation is more pronounced in the humus horizon. In addition, as a result of motor activity, organic carbon is transferred from the litter horizon to the humus horizon.

Figure 3. Dependence of the C/N ratio (a), nitrogen content (b) and carbon content (c) in the L subhorizon of litter on the biomass of epi-endogeic earthworms in the forests of the Moskva–Oka plain

Significant correlations of the biomass of endogeic species were found only with the C/N ratio in A horizon (Fig. 5), where earthworms of this group are most active provided the humidity is sufficient. No significant correlations of endogeic species with nitrogen and carbon content were established.

Figure 4. Dependence of the C/N ratio (a), nitrogen content (b) and carbon content (c) in A horizon on the biomass of epi-endogeic earthworms in the forests of the Moskva–Oka plain

 

Figure 5. Dependence of the C/N ratio in A horizon on the biomass of endogeic earthworms in the forests of the Moskva–Oka plain and the Northwest Caucasus

The lack of mineral forms of nitrogen is one of the crucial limiting factors of plant mineral nutrition, since up to 90% of this element in soils is in the form inaccessible to plants (Mengel, 1996). The activity of earthworms is known to result in soil enrichment with nitrogen forms available for plants. Earthworm coprolites are rich with urea and ammonium ions. Digestive enzymes of earthworms boost the activity of nitrifying and ammonifying bacteria thus reducing the loss of free nitrogen, which is fixed in the form of compounds, ammonium nitrogen going into nitrites and nitrates (Kozlovskaja, 1976). Experiments with Eisenia nordenskioldi, which live in dark gray soil under broadleaf forests, have shown that the soil is enriched with active forms of amino nitrogen available for absorption by plant roots, as well as with free and bound amino acids (Kozlovskaja et al., 1983; Striganova et al., 1989). In experiments with epi-endogeic and endogeic earthworms it was shown that ammonium contained in earthworm coprolites is able to modify soil nitrification, causing long-term cumulative effects that are vastly superior to their direct effect (Bitjuckij et al., 2007). In experiments with anecic earthworms, it was shown that the available nitrogen content in the soil increased by 0.03 mg/kg for every 0.1 g of earthworm biomass (Andriuzzi et al., 2016). In natural ecosystems, the flow of soil nitrogen through earthworm populations amounts to dozens of kilograms per hectare per year (Lee, 1985; Parmelee and Crossley, 1988), which is necessary for the sustainable functioning of terrestrial ecosystems. Also, the soil is enriched with nitrogen through the death of earthworms: their annual mortality rate is on average 60% of the total population (Lavelle et al., 1998). In the soils of Central Europe, the nitrogen yield reaches 24 g/m² after the death of earthworms, which is comparable to the annual dose of mineral nitrogen fertilizers (100–200 kg of N per 1 ha). Earthworm biomass containing 65–75% of protein decomposes quickly in the soil, but nitrogen bound by microorganisms is washed out more slowly (Lee, 1985; Makeschin, 1997; et al.).

Earthworms contribute to a significant decrease in the C/N ratio in the soil due to their direct and indirect influence on the mineralization and humification of organic matter. Thanks to earthworms there is a three-fold decrease in the C/N ratio in the soil as compared to the litter fall (Striganova, 1968). There is experimental evidence of a significant decrease of the C/N ratio under the influence of different morpho-ecological groups of earthworms not only in forest soils. For epi-endogeic earthworms, this has been shown in vermicompost (Talashilkar et al., 1999), and for endogeic earthworms – in agricultural fields (Sandor, Schrader 2007; McDaniel et al. 2013).

Earthworms are more often classified as nitroliberants, i.e. soil organisms that have a strong influence on nitrogen migration (Kozlovskaja, 1976; Zhukov et al., 2000), primarily due to the humification of organic matter in the soil. However, earthworms as primary litter decomposers and secondary decomposers of dead plant residues also affect the migration of carbon in soils, so they can also be attributed to the group of carboliberants (mineralizing agents). According to our and literature data, the influence of different morpho-ecological groups of earthworms on the nitrogen content and the C/N ratio is similar in the horizons of their activity: the nitrogen content increases, the C/N ratio decreases. However, a differential functional approach is required in regard to the effect of earthworms on carbon content. The latest global meta-analysis shows that the presence of not only epigeic and anecic groups, but also of endogeic earthworms leads to a decrease in organic matter in the litter horizon, with the strongest effect being exerted by anecic earthworms (Huang et al., 2020).

Our study shows a possible significant negative effect of the group of epi-endogeic earthworms (L. rubellus) on litter store and the content of organic carbon in it. It is known that this species is often confined to rich soils and a high content of organic matter (Zhukov, 2004; Zhukovskaja et al., 2005, etc.). We have identified the relationship between the biomass of the epi-endogeic L. rubellus and increased carbon content in the humus horizon. This is probably due to the high trophic activity of these earthworms and high quality of rapidly decomposing litter fall (birch, linden, hazel). No significant correlations between the biomass of endogeic species and the level of carbon accumulation were revealed, but there is a general trend towards decreased organic carbon content in the humus horizon with an increase in the biomass of this group of species. Endogeic species feed on humus (Perel’, 1979; Zhukov, 2004); their coprolites show a decrease in the total mass of organic matter and an increase in ash content by 2–3% as compared to the soil (Lavelle, Martin, 1992; Angst et al., 2017). Endogeic species are not involved in active movement of litter and transfer of organic carbon to the underlying horizons. To obtain convincing results, more field experiments in forest soils are needed, and we intend to continue our research in this area. 

CONCLUSIONS:

1. With the change in the succession status of forests, the species composition and the set of morpho-ecological groups of earthworms become more complex, but there is no consistent replacement of any one group by others.
2. The species richness, diversity of morpho-ecological groups, and biomass of earthworms with similar granulometric composition of soils is determined by the litter quality: the most favorable type of litter fall for maintaining the functional diversity of earthworms is the mixed litter of broadleaf and coniferous species of the tree canopy, undergrowth, and shrubs.
3. Ambiguous effects of earthworms of different morpho-ecological groups on carbon accumulation in forest soils were revealed. Negative correlations were found between the total biomass of epigeic, epi-endogeic, and anecic earthworm species and the litter carbon content. In the humus horizon, the biomass of epi-endogeic species was positively correlated with the carbon content. This study revealed no relationship between the carbon content of the soil and the earthworm anecic species.
4. Indicators associated with carbon accumulation, i.e. the C/N ratio and the nitrogen content, show similar (unidirectional) correlations with the biomass of earthworms in the horizons of their activity: with an increase in the biomass of earthworms of different morpho-ecological groups, the C/N ratio decreases, whereas the nitrogen content increases.

ACKNOWLEDGEMENTS

The study was conducted within the framework of the state CEPF RAS assignment AAAA-A18-118052590019-7, the material was obtained using the grant of the Russian Science Foundation (project No. 16-17-10284).

REFERENCES

Abaturov B.D., Pochvoobrazujushhaja rol’ zhivotnyh v biosfere (Soil-forming role of animals in the biosphere), Biosfera i pochvy, Moscow: Nauka, 1976. pp. 53-69.

Alban D.H., Berry E.C., Effects of earthworm invasion on morphology, carbon, and nitrogen of a forest soil, Appl. Soil Ecol., 1994, Vol. 1, pp. 243-249.

Andriuzzi W.S., Schmidt O., Brussaard L., Faber J.H., Bolger T., Earthworm functional traits and interspecific interactions affect plant nitrogen acquisition and primary production, Applied Soil Ecology, 2016, Vol. 104, pp. 148-156.

Angst S., Mueller C.W., Cajthaml T., Angst G., Lhotakova Z., Bartuska M., Spaldonova A., Frouz J., Stabilization of soil organic matter by earthworms is connected with physical protection rather than with chemical changes of organic matter, Geoderma, 2017, Vol. 289, pp. 29-35.

Begon M., Harper J.L., Townsend C.R., Ecology: Individuals, Populations and Communities. Oxford: Blackwell Scientifi c Publications, 1986, 1068 p.

Berezina O.G., Struktura naselenija kollembol (Hexapoda, Collembola) reliktovogo lipovogo lesa (Gornaja Shorija, Kemerovskaja oblast’) (The spatial structure of springtails community (Hexapoda, Collembola) of the southern forest-steppe of Western Siberia), Evraziatskij jentomologicheskij zhurnal, 2016, Vol. 15, No 6, pp. 583-590.

Bitjuckij N.P., Solov’eva A.N., Lukina E.I., Olejnik A.S., Zavgorodnjaja Ju.A., Demin V.V., Byzov B.A., Jekskrety dozhdevyh chervej stimuljator mineralizacii soedinenij azota v pochve (Stimulating Effect of Earthworm Excreta on the Mineralization of Nitrogen Compounds in Soil), Pochvovedenie, 2007, No 4, pp. 468-473.

Bohlen P.J., Pelletier D.M., Groffman P.M., Fahey T.J., Fisk M.C., Influence of earthworm invasion on redistribution and retention of soil carbon and nitrogen in northern temperate forests, Ecosystems, 2004, Vol. 7, pp. 13-27.

Burtelow A.E., Bohlen P.J., Groffman P.M., Influence of exotic earthworm invasion on soil organic matter, microbial biomass and denitrification potential in forest soils of the northeastern United States, Appl. Soil Ecol., 1998, Vol. 9, pp. 197-202.

Curry J.P., Factors affecting the abundance of earthworms in soils. In: Edwards C.A. (Ed.). Earthworm Ecology, 2nd ed., CRC Press, Boca Raton, FL, 1994, pp. 91-113.

Frouz J., Liveckova M., Albrechtoa J., Chronakova A., Cajthaml T., … & Simackova H. Is the effect of trees on soil properties mediated by soil fauna? A case study from post-mining sites, Forest Ecology and Management, 2013, Vol. 309, pp. 87-95.

Geras’kina A.P., Preobrazovanija kompleksa dozhdevyh chervej v hode poslerubochnyh sukcescij v lesah Severo-Zapadnogo Kavkaza (Transformations of earthworm communities during post-logging successions in the forests of the Northwest Caucasus), Forest science issues, 2018, No 1, pp. 1-14.

Gilyarov M.S., Metody pochvenno-zoologicheskih issledovanij (Methods of soil and zoological research), Moscow: Nauka, 1975, 304 p.

Gleixner G., Soil organic matter dynamics: a biological perspective derived from the use of compound-specific isotopes studies, Ecological Research, 2013, Vol. 28, No 5, pp. 683-695.

Goncharov A.A., Struktura troficheskih nish v soobshhestvah pochvennyh bespozvonochnyh (mezofauna) lesnyh jekosistem (The structure of trophic niches in the communities of soil invertebrates (mesofauna) of forest ecosystems. Candidate’s biol. sci. thesis), Moscow: IPJeJe, 2014, 177 p.

Hirth J.R., Li G.D., Chan K.Y., Cullis B.R., Long-term effects of lime on earthworm abundance and biomass in an acidic soil on the south-western slopes of New South Wales, Australia, Applied Soil Ecology, 2009, Vol. 43, pp. 106-114.

Hoeffner K., Monard C., Santonja M., Cluzeau D., Feeding behaviour of epi-anecic earthworm species and their impacts on soil microbial communities, Soil Biology and Biochemistry, 2018, Vol. 125, pp. 1-9.

Holdsworth A.R., Frelich L.E., Reich P.B., Leaf litter disappearance in earthworm-invaded northern hardwood forests: role of tree species and the chemistry and diversity of litter, Ecosystems, 2012, Vol. 15, No 6, pp. 913-926.

Huang W., Gonzalez G., Zou X., Earthworm abundance and functional group diversity regulate plant litter decay and soil organic carbon level: A global meta-analysis, Applied Soil Ecology, 2020, Vol. 150, pp. 1-15.

Klassifikacija i diagnostika pochv Rossii (Classification and diagnostics of Russian soils), Shishov L.L., Tonkonogov V.D., Lebedeva I.I., Gerasimova M.I. (Compl.), Smolensk: Ojkumena, 2004, 342 p.

Kozlovskaja L.S., Archegova I.B., Rakova H.N., Biohimicheskoe vozdejstvie pochvennyh bespozvonochnyh na rastitel’nye ostatki (Biochemical effects of soil invertebrates on plant debris), Bolotnye biogeocenozy i ih izmenenija v rezul’tate antropogennogo vozdejstvija, Leningrad: Nauka, 1983, pp. 24-26.

Kozlovskaja L.S., Rol’ pochvennyh bespozvonochnyh v transformacii organicheskogo veshhestva bolotnyh pochv (The role of soil invertebrates in the transformation of organic matter of bog soils), Leningrad, 1976, 211 p.

Kuznecova A.I., Lukina N.V., Tihonova E.V., Gornov A.V., Gornova M.V., Smirnov V.E., Geras’kina A.P., Shevchenko N.E., Teben’kova D.N., Chumachenko S.I., Akkumulyaciya ugleroda v peschanyh i suglinistyh pochvah ravninnyh hvojno-shirokolistvennyh lesov v hode poslerubochnyh vosstanovitel’nyh sukcessij (Сarbon stock in sandy and loamy soil of coniferous-deciduous forestsat the different stages of successions), Pochvovedenie, 2019, No 7, pp. 803-816.

Lavelle P., Martin A., Small-scale and large-scale effects of endogeic earthworms on soil organic matter dynamics in soils of the humid tropics, Soil Biology and Biochemistry, 1992, Vol. 24, No. 12, pp. 1491-1498.

Lavelle P., Pashanasi B., Charpentier F., Gilot C., Rossi J.-P., …& Bernier N., Large- scale effects of earthworms on soil oranic matter and nutrient dynamics, Edwards C.A. (Ed.), Earthworm ecology, St. Lucie Press, 1998, pp.103-122.

Lee K.E., Earthworms. Their ecology and relationships with soils and land use, Academic Press, 1985, 411 p.

Lukina N.V., Tihonova E.V., Shevchenko N.E., Gornov A.V., Kuznecova A.I., …  & Shanin V.N., Akkumuljacija ugleroda v lesnyh pochvah i sukcessionnyj status lesov (Carbon accumulation in forest soils and forest succession status), N.V. Lukinа (Ed.), Moscow: KMK, 2018, 232 p.

Makeschin F., Earthworms (Lumbricidae: Oligochaeta): Important promoters of soil development and soil fertility, G. Benckiser (Ed.), Fauna in soil ecosystems. Recycling processes, nutrient fluxes and agricultural production, Florida: CRC Press, 1997, pp. 173-223.

McDaniel J.P., Stromberger M.E., Barbarick K.A., Cranshaw W., Survival of Aporrectodea caliginosa and its effects on nutrient availability in biosolids amended soil, Applied soil ecology, 2013, Vol. 71, pp. 1-6.

Mengel K., Turnover of organic nitrogen in soils and its availability to crops, Plant and Soil, 1996, Vol. 181, pp. 83-96.

Metodicheskie ukazanija po kolichestvennomu opredeleniju obema pogloshhenija parnikovyh gazov (Guidelines for the quantification of greenhouse gas absorption), Rasporjazhenie Minprirody Rossii 30.06.2017, No 20-r, 108 p.

Moore J.-D., Ouimet R., Bohlen P.J., Effects of liming on survival and reproduction of two potentially invasive earthworm species in nothern forest Podzol, Soil Biology and Biochemistry, 2013, Vol. 64, pp. 174-180.

Nacional’nyj atlas pochv Rossijskoj Federacii (National Atlas of Soils of the Russian Federation), Shoba S.A., Aljabina I.O., Urusevskaja I.S., Chernova O.V., Moskow: Astrel’, 2011, 632 p.

Novara A., Rühl J., La Mantia, T., Gristina L., La Bella, S., Tuttolomondo T., Litter contribution to soil organic carbon in the processes of agriculture abandon, Solid Earth, 2015, Vol. 6, No 2, pp. 425-432.

Parmelee R.W., Crossley Jr., Earthworm production and role in the nitrogen cycle of a no-tillage agroecosystem on the Georgia piedmont, Pedobiologia, 1988, Vol. 32, pp. 353-361.

Perel’ T.S., Rasprostranenie i zakonomernosti raspredelenija dozhdevyh chervej fauny SSSR (Distribution and distribution patterns of earthworms of the fauna of the USSR), Moskow: Nauka, 1979, 272 p.

Pulleman M.M., Six J., Uyl A., Marinissen J.C.Y., Jongmans A.G., Earthworms and management affect organic matter incorporation and microaggregate formation in agricultural soils, Appl. Soil Ecol., 2005, Vol. 29, pp. 1-15.

Sandor M., Schrader S., Earthworms affect mineralization of different organic amendments in a microcosm study, Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture, 2007, Vol. 63, pp. 442-447.

Sariyildiz T., Effects of tree canopy on litter decomposition rates of Abies nordmanniana, Picea orientalis and Pinus sylvestris, Scandinavian journal of forest research, 2008, Vol. 23, No. 4, pp. 330-338.

Sariyildiz T., Küçük M., Litter mass loss rates in deciduous and coniferous trees in Artvin, northeast Turkey: Relationships with litter quality, microclimate, and soil characteristics, Turkish journal of Agriculture and Forestry, 2008, Vol. 32, No. 6, pp. 547-559.

Shevchenko N.E., Kuznecova A.I., Teben’kova D.N., Smirnov V.E., Geras’kina A.P., Gornov A.V., Tihonova E.V., Lukina N.V., Sukcessionnaya dinamika rastitel’nosti i zapasy pochvennogo ugleroda v hvojno-shirokolistvennyh lesah severo-zapadnogo Kavkaza (The succession dynamics of vegetation and carbon stocks in coniferous-deciduous forests of the north-western Caucasus), Lesovedeniе, 2019, No 3, pp. 163-176.

Striganova B.R., Issledovanie roli mokric i dozhdevyh chervej v processah gumifikacii razlagajushhejsja drevesiny (Investigation of the role of woodlice and earthworms in the processes of humification of decaying wood), Pochvovedenie, 1968, №. 8, pp. 85-90.

Striganova B.R., Kozlovskaja L.S., Chernobrovkina N.P., Kudrjasheva I.V., Pishhevaja aktivnost’ dozhdevyh chervej i soderzhanie aminokislot v temnoseroj lesnoj pochve (Alimentative activity of earthworms and content of aminoacids in the dark grey forest soil), Pochvovedenie, 1989, No 5, pp. 44-51.

Striganova B.R., Pitanie pochvennyh saprofagov (Nutrition of soil saprophages), Moskow: Nauka, 1980, 243 p.

Striganova B.R., Sukcessii zhivotnogo naselenija pochvy v processe pervichnogo pochvoobrazovanija (Successions of the animal population of the soil in the process of primary soil formation), Rannjaja kolonizacija sushi, Moskow: PIN RAN, 2012, pp. 177-195.

Suarez E.R., Fahey T.J., Yavitt J.B., Groffman P.M., Bohlen P.J., Patterns of litter disappearance in a northern hardwood forest invaded by exotic earthworms, Ecological Applications, 2006, Vol. 16, No 1, pp. 154-165.

Talashilkar S.C., Bhangarath P.P., Mehta V.B., Changes in chemical properties during composting of organic residues as influenced by earthworm activity, Journal of the Indian Society of Soil Science, 1999, Vol. 47, pp. 50-53.

Vsevolodova-Perel’ T.S., Dozhdevye chervi fauny Rossii. Kadastr i opredelitel’ (Earthworms of Russia. Cadastr and key-book.), Moskow: Nauka, 1997, 101 p.

Vsevolodova-Perel’ T.S., Gryuntal’ S.Yu., Kudryasheva I.V., Nadtochij S.E., Golovach S.I., Matveeva A.A., Osipov V.V., Karpachevskij L.O., Rastvorova O.G., Struktura i funkcionirovanie pochvennogo naseleniya dubrav Srednerusskoj lesostepi (The structure and functioning of the soil population of the oak forests of the Central Russian forest-steppe). Moscow: Nauka, 1995, 152 p.

World Reference Base for Soil Resources, International soil classification system for naming soils and creating legends for soil maps. World Soil Resources Reports, IUSS Working Group. Rome: FAO, 2015, 203 р.

Zhukov A.V., Dozhdevye chervi kak komponent biogeocenoza i ih rol’ v zooindikacii (Earthworms as a component of biogeocenosis and their role in zooindication), Ґruntoznavstvo, 2004, Vol. 5, No 1-2, pp. 44-57.

Zhukov A.V., Jekologicheskoe raznoobrazie zhivotnogo naselenija pochv pojmennyh biogeocenozov reki Samara (Ecological diversity of the animal population in the soils of floodplain biogeocenoses of the Samara River), Vіsnik Dnіpropetrovs’kogo unіversitetu. Bіologіja. Ekologіja, 2000, No 7. pp. 73-79.

Zhukovskaja E.A., Kodolova O.P., Pravduhina O.Ju., Varne A.Zh., Boloteckij N.M., Issledovanie geneticheskogo raznoobrazija dozhdevogo chervja Lumbricus rubellus Hoff. (Oligochaeta, Lumbricidae) (Study of genetic diversity of earthworm Lumbricus rubellus Hoff. (Oligochaeta, Lumbricidae), Izvestija Rossijskoj akademii nauk. Serija biologicheskaja, 2005. No 5. pp. 625-627.

 

Reviewer: candidate of Biological Sciences, Senior Research Officer Zenkova I.V.

]]> https://jfsi.ru/4-1-2021-ershovsochilova/ Mon, 29 Mar 2021 07:07:14 +0000 https://jfsi.ru/?p=4113

Original Russian Text © 2020 D.V. Ershov, E.N. Sochilova published in Forest Science Issues Vol. 3, No. 4, pp. 1-8

D.V. Ershov *, E.N. Sochilova

 

Center for Forest Ecology and Productivity of the RAS,

Profsoyuznaya st. 84/32 bldg. 14, Moscow 117997, Russian Federation

 

^*E-mail: dvershov67@gmail.com

Received: 14.12.2020

Accepted: 12.27.2020

The paper presents the results of assessing pyrogenic emissions of carbon compounds in Russian forests for 2020 using remote monitoring methods. The area of forests damaged by fires was 6.5 mln ha, whereas the amount of carbon emissions was 36.5 MtC. Although the total area of damage is higher than the average annual values, the amount of pyrogenic carbon emissions is lower than the average annual ones. In absolute terms, the year corresponds to 2016. We registered an increase in annual carbon emissions from fires since the abnormal 2012. A preliminary analysis of the entire observation period for fires suggests that 2021 may be the next abnormal year after the years of 2003 and 2012 in terms of forest fires and direct pyrogenic carbon emissions into the atmosphere.

Key words: forest fires, pyrogenic emissions, carbon, remote monitoring, forest fuel load

Estimates of direct annual emissions of carbon dioxide (CO₂) and other greenhouse gases (GHG) to the atmosphere from forest fires are needed to calculate the carbon budget in forests. Many current approaches use the results of the analysis of burned forested areas and data on the pre-fire stock volume of forest fuel load (FFL) biomass for modelling of pyrogenic carbon emissions  (Kasischke, Bruhwiler, 2002; Isaev et al., 2002; Rinsland et al., 2007; Junpen et al., 2011; Dolman et al., 2012; Zamolodchikov et al., 2017). The method developed at the CEPF RAS and modified by the authors in different years provides for the calculation of the stock volume of the main burn conductors of FFL before the fire (Sochilova et al., 2009). Further, the type and intensity of fire are determined by satellite products (Stytsenko et al., 2013), as well as the corresponding FFL consumption and the volumes of GHG (Ershov et al., 2009) emitted during combustion in the Russian forests. The data on burned areas and fire forest disturbances are formed in the IKI-Monitoring Center for Collective Use (Lupyan et al., 2019). The advantage of the method is the estimation of direct pyrogenic carbon emissions on the basis of spatial analysis of fire type maps, fire intensity and pre-fire FFL stock volumes (Isaev et al., 2002). As a result we can estimate emitted carbon during forest fires at different spatial levels of the territory of Russia.

The method was tested on Russian forests at the national level in the period from 2006 to 2015 using the TerraNorte RLC vegetation map, pre-fire FFL stocks and burn severity levels of forests damaged by fires (Ershov et al., 2016). Currently, we use the developed technology for the annual assessment of direct fire carbon emissions in Russian forests based on satellite monitoring data. The latest information on fire emissions over a long-term observation period was presented at the conference Contemporary Problems … held by RAS Space Research Institute (Ershov, 2019). According to satellite monitoring data (2002–2018), the total area of forests damaged by fires during the specified period was 78.6 mln ha, whereas the amount of direct fire carbon emissions was 578.5 MtC.

Table 1 presents statistics on direct fire carbon and GHG emissions for 10 years –from 2010 to 2019. Figure 1 shows the dynamics of damaged areas and volumes of specific carbon emissions over a ten-year period. According to satellite monitoring data, the total area of forests damaged by fires for the defined period was 51.1 mln ha; direct fire carbon emissions amounted to 375.1 MtC. Annually, the average area of damaged forests in Russia is 5.1 (± 2.0) mln ha, while emissions are estimated at 37.5 (± 12.3) MtC per year. According to satellite monitoring data, 2020 is comparable to 2016 in terms of the area of forests damaged by fires and carbon emissions. Although the area of damaged forests exceeds the average long-term values by 1.4 mln ha, absolute carbon emissions are less by 0.91 MtC. GHG emissions are also less than the average annual values over a ten-year period. Thus, when compared with the data obtained for the period from 2010 to 2019, the level of pyrogenic emissions in 2020 was average.

The analysis of the entire time series of pyrogenic carbon emissions in the period from 2002 to 2020 gave interesting results (Fig. 2). We registered two anomalous years, namely 2003 and 2012, in which the absolute pyrogenic emissions were 127.1 MtC and 83.8 MtC, respectively. The time interval between the two anomalous years is 9 years. Probably, 2021 may turn out to be the next extraordinary or anomalous year in terms of fires and the scale of pyrogenic carbon emissions in Russia, since there have been no anomalous years since 2012.

Table 1. Estimates of direct emissions of carbon and greenhouse gases from forest fires over the past 10 years of satellite observations in the territory of the Russian Federation

Year	Carbon emissions, tC	Damaged area, ha	Specific С emissions, t/ha	Greenhouse gas emissions, t
				CO2	CO	CH4	N2O	NOx
2010	15,321,461	2,107,599	7.27	56,178,690	2,145,005	245,143	1,685	60,914
2011	26,770,414	3,850,295	6.95	98,158,185	3,747,858	428327	2945	106,432
2012	83,821,145	11,365,539	7.38	307,344,198	11,734,960	1,341,138	9,220	333,249
2013	28,093,793	3,420,556	8.21	103,010,574	3,933,131	449,501	3090	111,693
2014	35,882,796	4,441,315	8.08	131,570,251	5,023,591	574,125	3947	142,660
2015	20,413,097	3,691,087	5.53	74,848,024	2,857,834	326,610	2245	81,157
2016	37,188,902	6,341,329	5.86	136,359,307	5,206,446	595,022	4091	147,852
2017	40,089,468	3,334,361	12.02	146,994,716	5,612,526	641,431	4,410	159384
2018	43,339,633	6,622,768	6.54	158,911,988	6,067,549	693,434	4767	172,306
2019	44,213,928	5,904,418	7.49	162,117,736	6,189,950	707,423	4864	175,782
Total	375,134,637	51,079,267	7.34	1,375,493,669	52,518,849	6,002,154	41,264	1,491,429
Long-term average	37,513,464	5,107,927	7.53	137,549,367	5,251,885	600,215	4,126	149,143
CO*	12,282,064	1,960,469	1.8	45,034,234	1,719,489	196,513	1,351	48830
2020	36,603,092	6,465,819	5.66	134,211,337	5,124,433	585,649	4026	145,523
Relative to average long-term values	-910,372	+1,357,892	-1.68	-3,338,030	-127,452	-14,566	—100	-3,619

* the average deviation is calculated in accordance with the formula , where x is the annual value of the parameter (carbon and greenhouse gas emissions);  is the average value of the parameter for n (10) years.

The second important conclusion that can be drawn from the analysis of the results obtained is that the areas of damaged forests and the intensity of direct pyrogenic carbon emissions after 2012 increased by 1.4 times. Until 2012, the average area of damaged forests and carbon emissions amounted to 3.95 mln ha and 29.2 MtC, whereas over the past 9 years they amounted to 5.7 mln ha and 41.1 MtC, respectively. As a result, carbon emissions from 2003 to 2011 (9 years) are comparable to carbon emissions from fires from 2012 to 2018 (7 years).

A spatial analysis of the obtained estimates of carbon emissions from fires in Russia in 2020 (Fig. 3) shows that the main contribution is made by Uralian (Khanty-Mansi and Yamalo-Nenets autonomous areas), Siberian (Tomsk region, Krasnoyarsk territory, and Irkutsk region), and Far Eastern regions (Republic of Sakha (Yakutia), Trans-Baikal territory, and Amur region).

Figure 1. Dynamics of areas damaged by forest fires and specific direct pyrogenic carbon emissions (2010-2020)

Figure 2. Dynamics of annual carbon emissions from fires during 2002–2020

Figure 3. Map of distribution of direct specific fire carbon emissions (t/ha) in Russian forests in 2020

Figure 4 shows the deviation of the specific pyrogenic carbon emissions in 2020 relative to the long-term average values.

 

Figure 4. Map of deviations of direct pyrogenic carbon emissions in 2020 from averaged long-term values

In 2020, an excess of carbon emissions relative to long-term average values was observed in the forests of the western part of the Khanty-Mansiysk region, the northern part of the Perm territory and the Sverdlovsk region, the eastern part of the Krasnoyarsk territory, the northern and central regions of the Irkutsk Region and Yakutia, in the north of the Khabarovsk Territory and in most of the Magadan region, as well as on the forest lands of the Chukotka lands, and Kamchatka region. In the European part of Russia there are some local and fragmentary cases of a slight increase in carbon emissions over the long-term average values.

CONCLUSION

According to the estimates, in 2020 carbon emissions from forest fires in Russia amounted to 36.5 MtC. Although the area of damaged forests was 1.4 mln ha larger than the average annual values whereas pyrogenic carbon emissions were lower than the average annual values and corresponded in absolute values to 2016. We registered a 1.4-fold increase in annual direct carbon emissions from fires since 2012. In terms of carbon emissions from fires in Russia, the period from 2012 to 2018 (7 years) was comparable to the period from 2003 to 2011 (9 years). A preliminary analysis of the entire observation period for fires suggests that the anomalous year of 2021 may be ranked after 2003 and 2012 in terms of forest fires and direct pyrogenic carbon emissions, comparable with 2003 and 2012 in terms of forest damage.

ACKNOWLEDGEMENTS

Pyrogenic carbon emissions were statistically assessed within the framework of the state assignment of the CEPF RAS AAAA-A18-118052590019-7; remote monitoring data and geoinformation maps were processed with the support of the Russian Science Foundation (project No. 19-77-30015).

REFERENCES

Dolman A.J., Shvidenko A., Schepaschenko D., Ciais P., Tchebakova N., Chen T., van der Molen M.K., L. Belelli Marchesini, Maximov T.C., Maksyutov S., Schulze E.-D., An estimate of the terrestrial carbon budget of Russia using inventory-based, eddy covariance and inversion methods, Biogeosciences, 2012, Vol. 9, pp. 5323-5340.

Ershov D.V., Ocenka jemissij ugleroda ot pozharov v lesah Rossii na osnove rezul’tatov sputnikovogo monitoring (Assessment of carbon emissions from fires in Russian forests based on satellite monitoring), Sovremennye problemy distancionnogo zondirovanija Zemli iz kosmosa (Modern Problems of Remote Sensing of the Earth from Space), 17th All-Russian Open Conference, Space Research Institute of the Russian Academy of Sciences, 2019, p. 519.

Ershov D.V., Bartalev S.A., Isaev A.S., Sochilova E.N., Stycenko F.V., Metod ocenki pozharnyh jemissij parnikovyh gazov s ispol’zovaniem sputnikovyh dannyh: rezul’taty primenenija dlja lesov Rossii v 21 veke (Fire assessment method of greenhouse gas emission with satellite data: results of forest for Russia in the 21st century), Ajerokosmicheskie metody i geoinformacionnye tehnologii v lesovedenii, lesnom hozjajstve i jekologii (Aerospace Methods and GIS-Technologies in Forestry, Forest Management and Ecology), Proceedings of the VI All-Russian Conference, Moscow, Russia, April 20-22, 2016, pp. 12-17.

Ershov D.V., Kovganko K.A., Sochilova E.N., GIS-tehnologija ocenki pirogennyh jemissij ugleroda po dannym Terra-MODIS i gosudarstvennogo ucheta lesov (GIS-technology of fire carbon emission assessment using Terra-Modis products and state forest account data), Sovremennye problemy distancionnogo zondirovanija Zemli iz kosmosa, 2009, Issue 6, Vol. 2, pp. 365-372.

Isaev A.S., Korovin G.N., Bartalev S.A., Ershov D.V., Janetos A., Kasishke E., Sugart H., French N., Orlick B., Murphy T., Using remote sensing for assessment of forest wildfire carbon emissions, Climate Change, 2002, Vol. 55, pp. 235-249.

Junpen A., Garivait S., Bonnet S., Pongpullponsak A., Spatial and Temporal Distribution of Forest Fire PM10 Emission Estimation by Using Remote Sensing Information, International Journal of Environmental Science and Development, 2011, Vol. 2 (2), pp.156-161.

Kasischke E.S., Bruhwiler L.P., Emissions of carbon dioxide, carbon monoxide, and methane from boreal forest fires in 1998, J. Geophys. Res., 2002, Vol. 107, p. 8146.

Loupian E.A., Proshin A.A., Bourtsev M.A., Kashnitskii A.V., Balashov I.V., Bartalev S.A., Konstantinova A.M., Kobets D.A., Mazurov A.A., Marchenkov V.V., Matveev A.M., Radchenko M.V., Sychugov I.G., Tolpin V.A., Uvarov I.A., Opyt jekspluatacii i razvitija centra kollektivnogo pol’zovanija sistemami arhivacii, obrabotki i analiza sputnikovyh dannyh (CKP «IKI-Monitoring») (Experience of development and operation of the IKI-Monitoring center for collective use of systems for archiving, processing and analyzing satellite data), Sovremennye problemy distancionnogo zondirovanija Zemli iz kosmosa, 2019, Vol. 16, No. 3, pp. 151-170.

Rinsland C.P., Goldman A., Hannigan J.W., Wood S.W., Chiou, L.S., Mahieu E., Long-term trends of tropospheric carbon monoxide and hydrogen cyanide from analysis of high resolution infrared solar spectra, J. Quant. Spectrosc. Ra., 2007, Vol. 104, pp. 40-51.

Sochilova E.N., Ershov D.V., Korovin G.N., Metody sozdanija kart zapasov lesnyh gorjuchih materialov nizkogo prostranstvennogo razreshenija (Methods of course resolution forest fuel load mapping), Sovremennye problemy distancionnogo zondirovanija Zemli iz kosmosa, 2009, Issue 6, Vol. 2, pp. 441-449.

Stytsenko F.V., Bartalev S.A., Egorov V.A., Loupian E.A., Metod ocenki stepeni povrezhdenija lesov pozharami na osnove sputnikovyh dannyh MODIS (Post-fire forest tree mortality assessment method using MODIS satellite data), Sovremennye problemy distancionnogo zondirovanija Zemli iz kosmosa, 2013, Vol. 10, No. 1, pp. 254-266.

Zamolodchikov D.G., Grabovsky V.I., Shulyak P.P., Chestnykh O.V., Sovremennoe sokrashhenie stoka ugleroda v lesa Rossii (Recent decrease of carbon sink to Russian forests), Doklady Akademii nauk, 2017, Vol. 476, No. 6, pp. 719-721.

 

Reviewer: PhD in agriculture, Deputy Research Director of RAS Forest Research Institute of Karelian Research Centre S.A. Moshnikov

]]> https://jfsi.ru/4-1-2021-ermolov/ Mon, 29 Mar 2021 06:49:15 +0000 https://jfsi.ru/?p=4099

Original Russian Text © 2020 S.A. Ermolov published in Forest Science Issues Vol. 3, No. 3, pp. 1-24

S.A. Ermolov

 

Center for Forest Ecology and Productivity of the Russian Academy of Sciences

Profsoyuznaya st. 84/32 bldg. 14, Moscow 117997, Russian Federation

E-mail: ermserg96@gmail.com

Received 06.04.2020

Accepted 02.06.2020

 

Earthworms form an essential group of soil macrofauna that performs a number of ecosystem functions in forests. Studies of the species composition and population density of earthworms were conducted in many regions of Russia; however, the fauna of Lumbricidae of Novosibirsk area remained unexplored for a long time. The objective of this work is to carry out a comparative analysis of earthworm population in coniferous and small foliage forests of the forest-steppe Ob region (Novosibirsk area) and to identify the correlation between the fauna composition and the basic physical and chemical properties of the soil. The study was conducted in pine forests and birch-aspen forests. The main method of registration was layer-by-layer excavation of soil with hand sorting of soil samples and analysis of forest deadwood. Some soil parameters were also measured. Data of the species composition and population density of earthworms for each habitat are given. The studied habitats were classified according to the ratio of the earthworm living forms. It was found that soil humidity is the most significant factor for the group of epigeiс and epi-endogeiс species. The diversity of epigeiс and epi-endogeiс earthworm species in forests is largely supported by deadwood. The Asian subspecies Eisenia nordenskioldi nordenskioldi was subjected to morphometric analysis confirming its characteristic polymorphism.

Key words: earthworms, living forms, Eisenia nordenskioldi nordenskioldi, Novosibirsk area, small foliage forests, deadwood, soil properties

 In forest ecosystems, earthworms form one of the most important groups of soil-forming animals. As saprophages, earthworms of different species and living forms to varying degrees contribute to transformation of organic matter: epigeiс and epi-endogeiс earthworms decompose plant remains, thereby supporting the formation of the humus horizon; anecic earthworms help the organic matter to penetrate into the deep layers of soil; endogeic earthworms living at different depths consume humus, thus carrying out mineralization of organic matter and transfer of C and N compounds in the soil (Perel’, 1975; 1979; Holdsworth et al., 2008). The presence of various species and living forms of earthworms, as well as their estimated population density, indicate the state of forest soils (Chekanovskaja, 1960; Akkumuljacija…, 2018).

Soil is not the only habitat for earthworms. They also inhabit forest litter, live in piles of animal dung, and are abundant in deadwood, contributing to its destruction. The latter is most important for forest ecosystems, where deadwood helps to maintain not only the species diversity, but also the functional diversity of earthworms (Geraskina, 2016b, 2016c; Ashwood et al., 2019).

Studies of earthworms in forest ecosystems have been conducted in many regions of Russia. The territory of the Russian Plain, the Urals, the Northwestern and Central Caucasus, and the Far East were studied in more detail (Perel’, 1958; Penev et al., 1994; Shashkov, 2003; Rapoport, 2010; Ganin, 2013). In Western Siberia, the forests of Altai and Mountain Shoriya have been studied (Perel’, 1994; Musienko, 2019), whereas in the territory of Novosibirsk area, in particular in the area of the forest-steppe Ob region, which comprises a variety of forest landscapes (Mugako, 2008; Atlas…, 2002), such studies are virtually non-existent. Since studying of the biotopic distribution and molecular genetic diversity of earthworms (Shehovcov et al., 2016; Kim-Kashmenskaja, 2016; Ermolov, 2018, 2018a, 2019; Shehovcov et al., 2020) has recently begun in this region, we decided to contribute to this research by studying the forest ecosystems of the forest-steppe Ob region, Novosibirsk area.

The objective of this work is to conduct a comparative analysis of the earthworm population of coniferous and small foliage forests of the forest-steppe Ob region of Novosibirsk area and to identify the relationship of its composition with the main environmental factors.

Tasks:

1. To compare the species composition and complexes of earthworms living forms (Lumbricidae) in coniferous (pine forests) and small foliage (birch-aspen) forests.
2. To study the earthworm population of forest deadwood as a specific habitat of soil saprophages.
3. To investigate the relationship between the species composition of earthworms and the main physical and chemical properties of forest soils.
4. To provide rationalization for distinguishing between large-sized and small-sized earthworms of the Eisenia nordenskioldi nordenskioldi subspecies according to their external morphological features.

MATERIAL AND METHODS

Research area. Novosibirsk area is traditionally divided into five natural and geographical regions: Vasyuganye, Baraba, Kulunda, Ob region, and Salair (Mugako, 2008; Atlas…, 2002). The territory of the forest-steppe Ob region includes typical meadow-steppe landscapes and mixed-herb forests as well as small foliage (birch-aspen) herb forests on sod-podzolic and gray forest soils (Atlas…, 2002), where the material for the study was sampled. Samplings were carried out in tall-herb-fern pine forests (Zael’covskij, Kudrjashovskij, Chemskoj, pine forests in the vicinity of Baryshevo village and Sosnovka settlement); in birch-aspen forests: tall-herb-fern birch-aspen forests (in the vicinity of Bykovo village, Morozovo and Kol’covo settlements), tall-herb-goutweed birch forest (in the vicinity of Shelkovichiha station), low-herb birch forest (in the vicinity of Verh-Tula village). The following types of soils were found in the studied territories: sod-low podzolic sandy soils, sod-podzolic and gray forest (mostly dark) soils (Fig. 1) (Pochvennaja karta…, 2007).

Earthworm sampling. Earthworm sampling in the soils involved layer-by-layer excavation of soil with hand sorting (Metody…, 1975). A square 50 cm sides was marked on the selected plot of forest soil. First, the litter was sorted, then the soil layers with a thickness of 0–2 cm, 2–5 cm, 5–10 cm and more than 10 cm (~up to 40 cm or deeper) were excavated with subsequent hand sorting. 8 soil pits were taken in each studied forest.

Earthworm sampling in deadwood: the length and diameter of the fallen trunks at decomposition stage 2–3 or their fragments were measured in several places with subsequent hand sorting of the bark, moss cover and rotting wood. If possible, the deadwood was sorted all the way to the ground (Geraskina, 2016b, 2016c).

The collected worms were euthanized in 2 % formalin solution and fixed in 4 % formalin solution with glycerine (Chekanovskaja, 1960). The species composition of earthworms was determined according to the field guide by T. S. Vsevolodova-Perel’ (Vsevolodova-Perel’, 1997).

Individuals of the Eisenia nordenskioldi nordenskioldi subspecies, which have characteristic pronounced polymorphism (Perel’, 1994, 1997), were subjected to morphometric analysis. During the analysis the following parameters (Shehovcov et al., 2020) were measured: segment number (SN), body length (BL, mm), body width at the widest point (BW, mm), clitellum length (CL, mm), clitellum width (CW, mm), body weight of the worm fixed in formalin solution (W, g). Since large-sized worms suitable for morphometry (i. e., adult worms with a distinct clitellum) were rare, all the individuals found in pine forests and small foliage forests were divided into two general groups. Small-sized worms were grouped according to specific habitats: two for deadwood (Kol’covo, Bykovo) and one for soil (Verh-Tula), where the number of the subspecies was the highest.

Figure 1. A fragment of the soil map of Novosibirsk area (Pochvennaja karta…, 2007) with the studied pine and small foliage forests
Note: Pine forests: 1 – vicinity of Sosnovka settlement; 2 – Kudrjashovskij pine forest; 3 – Zael’covskij pine forest; 4 – vicinity of Baryshevo village; 5 – Chemskoj pine forest; Small foliage forests in the vicinity of villages: 6 –Shelkovichiha station; 7 – Bykovo village; 8 – Kol’covo settlement; 9 – Morozovo settlement; 10 – Verh-Tula village

The sampling was carried out in the summer of 2019. In total, 80 soil samples were taken during the season, 5.13 m³ of deadwood was sorted, and 3394 individuals of earthworms of various species and living forms were collected.

Soil samples analysis. During earthworm sampling in all the studied habitats, the thickness of the litter and the humus horizon were measured for each soil pit (with an accuracy of 1 mm); soil samples were taken from each sample layer (0–2, 2–5, 5–10, 10–30 cm) for further laboratory analysis.

Soil humidity (hygroscopic humidity) and acidity (actual acidity, water pH) were determined in soil samples. To calculate the moisture content in the soil, fresh wet samples were packed in aluminium cups and weighed, then dried to an air-dry state and re-weighed. The percentage of moisture (W) was calculated using the formula:

Where m₁ is the mass of wet soil with a cup and a lid, g; m₀ is the mass of dried soil with a cup and a lid, g; m is the mass of an empty cup with a lid, g (GOST 28268-89).

Potentiometric method was used to measure acidity: a suspension was prepared in distilled water from 20 g of dry soil sample sifted through a fine sieve, and then a MI-150 electrode of the pH meter was placed into it (Vorob’eva et al., 2012).

Data processing. The obtained data on the population density of earthworms were calculated per unit area for soil samples (individuals/m²), and per unit volume (individuals/m³) for deadwood; the volume of the deadwood was calculated according to the formula: V=π*r²*h, where r is the average radius of the trunk; and h is the height of the trunk (Geraskina, 2016b, 2016c).

The Spearman’s rank correlation coefficient was used to calculate correlations between the earthworm population density and the physical and chemical properties of the soil.

For each habitat, average data values for soil humidity and acidity were calculated. Average values are also calculated for the litter thickness and the humus horizon thickness. Then the data obtained were compared with the density of the earthworm population in each habitat group. Worms belonging to the main morpho-ecological types were considered separately (Perel’, 1975, 1979): worms that feed on the soil surface (epigeic and epi-endogeic) and worms that feed on soil humus (upper-soil-layer and middle-soil-layer endogeic earthworms). The correlation analysis did not take into account the data on the density of endogeic earthworm population in the pine forest in the vicinity of Baryshevo village due to the low density of worms in this group (10 individuals/m²).

Samples with morphometric data of E. nordenskioldi nordenskioldi earthworms were compared using the Mann–Whitney U-test.

Clustering of habitats according to the composition of living forms was performed in the Past software. The initial data were normalized by the dominance index: in all habitats, the population density of earthworms of each living form was calculated as a proportion of the total population. This allowed us to obtain uniform units of measurement. To measure the distance between objects, the Euclidean distance was used, and the Ward’s method was used to construct dendrograms (Vjen Rajzin, 1980).

RESULTS

Earthworm population in pine forests. In the studied pine forests, both cosmopolitan earthworm species (Dendrobaena octaedra (Savigny, 1826), Lumbricus rubellus (Hoffmeister, 1843), Aporrectodea caliginosa caliginosa (Savigny, 1826), Dendrodrilus rubidus subrubicundus (Eisen, 1874) and worms inhabiting mainly the Asian part of the Russian Federation and adjacent territories (Eisenia nordenskioldi nordenskioldi (Eisen, 1879), Eisenia nordenskioldi pallida Malevič, 1956) were found.

The highest density of earthworm population was observed in the Zael’covskij pine forest (174 individuals/m²), whereas it was the lowest in the pine forest in the vicinity of Baryshevo village (30 individuals/m²), where worms were not found in all pits, and some species were found only once (Table 1). The most diverse species composition was found in the Kudrjashovskij pine forest (4 subspecies, 2 species; 172 individuals/m² in total, some species were found only once), and the least diverse species composition was found in the pine forest in the vicinity of Sosnovka settlement (2 subspecies, 1 species; 124 individuals/m² in total), where, with the exception of D. octaedra, there were no cosmopolitan species. The Chemskoj pine forest is similar in species composition to the Kudrjashovskij pine forest, and in terms of the population density of worms it is similar to the pine forest in Sosnovka settlement (3 subspecies, 2 species; 124 individuals/m² in total). In all the studied pine forests, the E. n. nordenskioldi subspecies was represented by both small-sized and large-sized earthworms.

Table 1. Population of earthworms (Lumbricidae) in pine forests (X ± SE)

Type of biotope	Place of sampling	Living forms	Species	Population density of the species, individuals/m2	Proportion of the living form, %
Tall-herb-fern pine forests	Chemskoj pine forest	Epigeiс	D. octaedra	4±2	3
		Epi-endogeic	L. rubellus	2±1	11
			E. n. nordenskioldi (small-sized)	6±2
			E. n. nordenskioldi (large-sized)	6±2
		Endogeic (middle-soil-layer)	A. c. caliginosa	84±23	86
			E. n. pallida	22±8
	Kudrjashovskij pine forest	Epigeiс	D. octaedra	16±3	11
			D. r. subrubicundus	3±1
		Epi-endogeic	Lumbricus rubellus	1±1	10
			E. n. nordenskioldi (small-sized)	11±3
			E. n. nordenskioldi (large-sized)	5±2
		Endogeic (middle-soil-layer)	A. c. caliginosa	80±33	79
			Eisenia nordenskioldi pallida	57±20
	Zael’covskij pine forest	Epigeiс	Dendrobaena octaedra	14±8	8
		Epi-endogeic	Lumbricus rubellus	42±16	32
			E. n. nordenskioldi (small-sized)	10±4
			E. n. nordenskioldi (large-sized)	4±1
		Endogeic (middle-soil-layer)	A. c. caliginosa	42±26	60
			E. n. pallida	62±20
	Pine forest in the vicinity of Sosnovka settlement	Epigeiс	D. octaedra	16±7	13
		Epi-endogeic	E. n. nordenskioldi (small-sized)	32±17	35
			E. n. nordenskioldi (large-sized)	12±8
		Endogeic (middle-soil-layer)	E. n. pallida	64±43	52
	Pine forest in the vicinity of Baryshevo village	Epigeiс	D. octaedra	9±3	34
			D. r. subrubicundus	1±1
		Epi-endogeic	E. n. nordenskioldi (small-sized)	9±3	33
			E. n. nordenskioldi (large-sized)	1±1
		Endogeic (upper-soil-layer)	O. lacteum (small-sized)	4±4	13
		Endogeic (middle-soil-layer)	E. n. pallida	6±3	20

According to the ratio of living forms, all the studied pine forests were divided into three groups:

1. pine forests with a predominance (up to 86 %) of middle-soil-layer endogeic earthworms (Chemskoj and Kudrjashovskij pine forests);
2. pine forests, where epigeiс and epi-endogeiс earthworms make up about 50 % of the population (Zael’covskij pine forest and the vicinity of Sosnovka settlement);
3. pine forest, where the ratio of all living forms is approximately the same (the vicinity of Baryshevo village) (Fig. 2; Table 1).

Figure 2. The ratio of living forms of earthworms in pine forests
Note: 1 – epigeiс; 2 – epi-endogeic; 3 – upper-soil-layer endogeic; 4 – middle-soil-layer endogeic

In the Chemskoj and Kudryashovskiy pine forests the species composition, forming complexes of living forms, was almost identical, whereas the Zael’covskij pine forest and the area in the vicinity of Sosnovka settlement revealed significant differences in species composition. Thus, the epi-endogeic earthworms in the Zael’covskij pine forest are mainly represented by L. rubellus, while in Sosnovka the only representative of this group is E. n. nordenskioldi. In the Zael’covskij forest, the middle-soil-layer endogeic earthworms are represented by A. c. caliginosa and E. n. pallida subspecies (the population density of A. c. caliginosa being considerably lower than in the Chemskoj and Kudrjashovskij pine forests), and in Sosnovka this form is represented only by E. n. pallida. In the pine forest in the vicinity of Baryshevo village, singular individuals of the upper-soil-layer endogeic Octolasion lacteum (Örley, 1885) was found, and the proportions of other species and living forms were approximately equal.

Earthworm population in small foliage forests. The species composition of earthworms in the studied small foliage forests was generally similar to that in the pine forests (Table 2). High population density of earthworms was observed in two tall-herb-fern birch-aspen forests (in the vicinity of Bykovo village – 16 individualsm² and in the vicinity of Morozovo settlement – 63 individualsm²) and in the tall-herb-goutweed birch forest (in the vicinity of Shelkovichiha station – 67 individualsm²). The O. lacteum species (small-sized) was also found in these forests (Shehovcov et al., 2020), its population density being the highest in the forest in the vicinity of Morozovo settlement (202 individuals/m²).

In the tall-herb-fern birch-aspen forest in the vicinity of Kol’covo settlement and in low-grass birch forest in the vicinity of Verh-Tula village, the population density of earthworms was significantly lower (Kol’covo – 55 individualsm², Verh-Tula – 7 individualsm²). Noteworthy is also low species diversity: only E. n. nordenskioldi, E. n. pallida and singular D. octaedra were found. Also, the low-grass birch forest (Verh-Tula) is the only habitat studied where the large-sized E. n. nordenskioldi was not found, population density of the small-sized form being relatively high (Table 2).

On the resulting dendrogram of the ratio of living forms (Fig. 3), all small foliage forests are divided into two large groups:

• in the forest in the vicinity of Morozovo settlement, upper-soil-layer endogeic earthworms ( lacteum) are the predominant living form (88 % of the population);
• the second group includes the rest of the forests, where the proportion of middle-soil-layer endogeic earthworms is about half of the total population. There are differences within this group: the three forests demonstrate a significant proportion of epigeiс and epi-endogeiс earthworms (epi-endogeic earthworms in the vicinity of Kol’covo settlement and Verh-Tula village, epigeiс earthworms in the vicinity of Shelkovichiha station), and in the forest in the vicinity of Bykovo village 33 % of the population is comprised of upper-soil-layer endogeic earthworms. It should also be noted that epi-endogeic earthworms in the forests in the vicinity of Kol’covo settlement and Verh-Tula village are represented only by n. nordenskioldi, and the middle-soil-layer endogeic earthworms – by E. n. pallida. In the forests in the vicinity of Bykovo village and Shelkovichiha station, both subspecies are also found, but these living forms are predominantly represented by L. rubellus and A. c. caliginosa, respectively (Table 2).

 

Figure 3. Ratio of living forms of earthworms in small foliage forests
 Note: here and elsewhere the legend is the same as for Fig. 2

Table 2. Earthworm (Lumbricidae) population in small foliage forests (X ± SE)

Type of biotope	Place of sampling	Living forms	Species	Population density, individuals/m2	Proportion of the living form, %
Tall-herb-fern birch-aspen forests	Vicinity of Bykovo village	Epigeiс	D. octaedra	5±2	2
		Epi-endogeic	L. rubellus	39±14	22
			E. n. nordenskioldi (small-sized)	8±3
			E. n. nordenskioldi (large-sized)	1±1
		Endogeic (upper-soil-layer)	O. lacteum (small-sized)	67±21	31
		Endogeic (middle-soil-layer)	A. c. caliginosa	95±34	45
			E. n. pallida	2±2
	Vicinity of Morozovo settlement	Epigeiс	D. octaedra	12±3	5
		Epi-endogeic	E. n. nordenskioldi (small-sized)	39±8	17
			E. n. nordenskioldi (large-sized)	6±2
		Endogeic (upper-soil-layer)	O. lacteum (small-sized)	202±29	77
		Endogeic (middle-soil-layer)	A. c. caliginosa	4±2	1
	Vicinity of Kol’covo settlement	Epigeiс	D. octaedra	6±3	11
		Epi-endogeic	E. n. nordenskioldi (small-sized)	23±6	44
			E. n. nordenskioldi (large-sized)	1±1
		Endogeic (middle-soil-layer)	E. n. pallida	25±6	45
Tall-herb-goutweed birch forest	Vicinity of Shelkovichiha station	Epigeiс	D. octaedra	64±16	25
			D. r. tenuis	3±2
		Epi-endogeic	L. rubellus	27±12	15
			E. n. nordenskioldi (small-sized)	8±4
			E. n. nordenskioldi (large-sized)	5±2
		Endogeic (upper-soil-layer)	O. lacteum (small-sized)	5±4	2
		Endogeic (middle-soil-layer)	A. c. caliginosa	146±48	58
			E. n. pallida	10±8
Low-herb birch forest	Vicinity of Verh-Tula village	Epigeiс	D. octaedra	1±1	1
		Epi-endogeic	E. n. nordenskioldi (small-sized)	26±5	36
		Endogeic (middle-soil-layer)	E. n. pallida	45±13	63

 

 

Earthworm population in forest deadwood. Deadwood suitable for earthworm sampling (Geraskina, 2016b, 2016c) was found only in five habitats: in three pine forests (Zael’covskij, Chemskoj, and in the vicinity of Baryshevo village) and in two small foliage forests (tall-herb-fern birch-aspen forests in the vicinity of Bykovo village and of Kol’covo settlement). The studied deadwood was represented by single fallen trunks of Pinus sylvestris and Betula pendula of different sizes, stage 2–3 of decomposition. Almost the entire population of deadwood was made up of epigeiс and epi-endogeic earthworms, with rare occasional endogeic earthworms found in the trunks of decomposition stage 3 (Table 3, Table 4). It is particularly remarkable that in the pine forest in the vicinity of Baryshevo village and birch-aspen forest in the vicinity of Kol’covo settlement, where the population density of earthworms in the soil was low, deadwood showed high population density and species composition diversity.

Table 3. Population of earthworms (Lumbricidae) in the deadwood of pine forests

Place of sampling	Stage of decomposition, type of wood	Living forms	Species	Population density, individuals/m3	Proportion of the living form, %
Tall-herb-fern pine forests
Zael’covskij pine forest	2, pine tree	Epigeiс	D. octaedra	101	88
			D. r. tenuis	8
		Epi-endogeic	L. rubellus	14	12
			E. n. nordenskioldi (small-sized)	1
Chemskoj pine forest	2, birch	Epigeiс	D. octaedra	64	54
			D. r. tenuis	48
		Epi-endogeic	E. n. nordenskioldi (small-sized)	84	40
		Endogeic (middle-soil-layer)	E. n. pallida	12	6
Pine forest in the vicinity of Baryshevo village	2, pine tree	Epigeiс	D. octaedra	192	99
			D. r. tenuis	169
		Epi-endogeic	E. n. nordenskioldi (small-sized)	4	1
	3, pine	Epigeiс	D. octaedra	12	44
			D. r. tenuis	13
		Epi-endogeic	E. n. nordenskioldi (small-sized)	14	25
		Endogeic (upper-soil-layer)	O. lacteum (small-sized)	17	29
		Endogeic (middle-soil-layer)	E. n. pallida	1	2
	3, birch	Epigeiс	D. octaedra	164	88
			D. r. tenuis	120
		Epi-endogeic	E. n. nordenskioldi (small-sized)	40	12

Table 4. Population of earthworms (Lumbricidae) in the deadwood of small foliage forests

Place of sampling	Stage of decomposition, type of wood	Living forms	Species	Population density, individuals/m3	Proportion of the living form, %
Tall-herb-fern birch-aspen forests
Vicinity of Bykovo village	2, birch No. 1	Epigeiс	D. octaedra	500		81
			D. r. tenuis	600
		Epi-endogeic	L. rubellus	20		19
			E. n. nordenskioldi (small-sized)	240
	2, birch No. 2	Epigeiс	D. r. tenuis	25		5
		Epi-endogeic	L. rubellus	100		95
			E. n. nordenskioldi (small-sized)	350
	3, birch	Epigeiс	D. r. tenuis	7		22
		Epi-endogeic	L. rubellus	6		77
			E. n. nordenskioldi (small-sized)	16
			E. fetida	2
		Endogeic (middle-soil-layer)	A. c. caliginosa	1		1
Vicinity of Kol’covo settlement	2, birch	Epigeiс	D. octaedra	4		30
			D. r. tenuis	50
			D. r. subrubicundus	62
		Epi-endogeic	E. n. nordenskioldi (small-sized)	273		70

The species composition of earthworms in the deadwood of the Chemskoj and Zael’covskij pine forests and in the birch-aspen forest in the vicinity of Bykovo village is similar to that in the soil of these habitats, with the exception of the D. r. tenuis subspecies (Eisen, 1874), which is common mainly in the deadwood (Geraskina, 2016a; Ermolov, 2018a). Also, deadwood of the forest in the vicinity Bykovo village was the only habitat where the epi-endogeic Eisenia fetida (Savigny, 1896) was found, which is synanthropic in Novosibirsk area (Ermolov, 2018, 2018a, 2019).

Deadwood was subjected to classification according to the ratio of living forms of earthworms (Fig. 4). Deadwood was divided into three groups:

• deadwood with a predominance of epigeiс earthworms;
• deadwood with a predominance of epi-endogeic forms;
• deadwood with the presence of endogeic earthworms.

Despite the similar ratio of living forms, deadwood within one group differs in terms of predominant types of earthworms belonging to the same living form. For example, in the first group, the deadwood of the Zael’covskij pine forest has the same ratio of living forms as that in the vicinity of Baryshevo village (Fig. 4). However, in the Zael’covskij pine forest, almost all epigeic earthworms belong to D. octaedra, epi-endogeic earthworms – to L. rubellus, and in the pine forest in the vicinity of Baryshevo village (as, indeed, in the other deadwood in this group) the epigeic earthworms are represented by D. octaedra and D. r. tenuis, with the population density ratio of almost 1:1 (Table 3, Table 4), and E. n. nordenskioldi (small-sized) represent the majority of epi-endogeic earthworms. In the group with the predominance of epi-endogeic earthworms, deadwood in the vicinity of Bykovo village was inhabited by three different representatives of this living form (L. rubellus, E. fetida, E. n. nordenskioldi (small-sized)), whereas in the vicinity of Kol’covo it was represented by E. n. nordenskioldi only (small-sized); also, only in the deadwood in the vicinity of Kol’covo the epigeic subspecies D. r. subrubicundus was common. In highly decomposed pine trunk in the pine forest in the vicinity of Baryshevo, endogeic earthworms O. lacteum that were also sporadically found in the soil of that forest, were found; in the deadwood of the Chemskoj pine forest the proportion of middle-soil-layer endogeic E. n. pallida was relatively high; there was no marked predominance among the other forms in the deadwood of this group.

Figure 4. The proportion of living forms of earthworms in the deadwood
Note: 1 – Baryshevo (pine, st. 2); 2 – Bykovo (birch 1, st. 2); 3 – Zael’covskij pine forest (pine, st. 2); 4 – Baryshevo (birch, st. 3); 5 – Baryshevo (pine, st. 3); 6 – Chemskoj pine forest (birch, st. 2); 7 – Bykovo (birch 2, st. 2); 8 – Bykovo (birch, st. 3); 9 – Kol’covo (birch, st. 2)

The relationship between soil properties and the species composition of earthworms. The measured physical and chemical soil properties in the studied pine forests and small foliage forests are shown below (Tables 5 and 6).

Table 5. Physical and chemical properties of pine forest soils (X ± SE)

Place of sampling	Litter thickness, cm	Humus horizon thickness, cm	Moisture content in the soil, %	Soil acidity, pH of the water
Chemskoj pine forest	3.3±0.1	6.8±0.4	20.06±1.88	5.81±0.08
Zael’covskij pine forest	2.3±0.2	10.4±0.5	30.44±3.21	5.72±0.06
Kudrjashovskij pine forest	2.4±0.1	9.9±0.7	25.25±2.22	5.38±0.04
Pine forest in the vicinity of Sosnovka settlement	3.5±0.3	5.0±0.4	34.81±3.65	5.36±0.05
Pine forest in the vicinity of Baryshevo village	3.6±0.2	10.5±0.7	22.50±2.87	5.96±0.07

Table 6. Physical and chemical properties of small foliage forest soils (X ± SE)

Name of the biotope	Litter thickness, cm	Humus horizon thickness, cm	Moisture content in the soil, %	Soil acidity, pH of the water
Vicinity of Bykovo village	1.6±0.2	9.9±1.1	28.00±2.24	5.68±0.09
Vicinity of Morozovo settlement	2.0±0.2	19.9±1.1	21.50±0.86	6.22±0.08
Vicinity of Kol’covo settlement	2.8±0.2	10.3±0.6	21.06±0.88	6.23±0.06
Vicinity of Shelkovichiha station	2.2±0.1	12.3±0.5	39.19±1.63	5.42±0.08
Vicinity of Verh-Tula village	3.4±0.2	9.8±0.7	17.56±0.75	6.35±0.08

The diagram for pine forests shows that soil humidity is the most significant factor affecting the population density of epigeiс and epi-endogeiс earthworms (Fig. 5). Their population density shows a significant correlation with the indicators of soil humidity (r_s=0.89; p <0.05; n=5). Earthworms of these groups live near the surface of the soil and are therefore more sensitive to drying out. In these habitats, moisture is retained mainly due to the litter, since sod-podzolic soils and sod-podzolic sandy soils typical of pine forests, retain very little moisture necessary for the normal life of earthworms. No correlations with other soil properties were found in this group.

No connection with soil characteristics other than humidity was found withing the group of endogeic earthworms. Positive connection was found between the population density of E. n. pallida and soil humidity (r_s=0.90; p<0.05, n=4) and negative connection between the population density of A. c. caliginosa and soil humidity (r_s=−0.90; p<0.05; n=4) (Fig. 6).

Figure 5. Correlation between the population density of epigeiс and epi-endogeiс earthworms and soil humidity in pine forests
Note: 1 — population density of epigeiс and epi-endogeiс earthworms; 2 – soil humidity

Figure 6. Correlation between the population density of endogeic earthworms and soil humidity in pine forests
Note: 1 — A. caliginosa caliginosa; 2 – E. nordenskioldi pallida; 3 – soil humidity

In small foliage forests with gray forest soils, positive correlations were found between the total density of epigeiс and epi-endogeiс earthworms and soil humidity (r_s=0.89; p <0.05; n=5) (Fig. 7). No significant correlations were found with other soil characteristics.

Figure 7. Correlation between the population density of epigeiс and epi-endogeiс earthworms and soil humidity in small foliage forests
Note: 1 — population density of epigeiс and epi-endogeiс earthworms; 2 – soil humidity

Figure 8. Diversity of species composition and population density of endogeic earthworms in small foliage forests
Note: 1 — E. nordenskioldi pallida; 2 – O. lacteum; 2 – A. caliginosa caliginosa

In the group of endogeic earthworms, no correlation between the total population density and the population density of individual species with soil properties was found. However, it should be noted that, unlike in the pine forests, the species composition and population density of this group of earthworms in small foliage forests vary greatly (Fig. 8). The forest in the vicinity of Morozovo settlement with a thick humus horizon (19.9 cm) and slightly acidic soil reaction (pH_water = 6.22) is dominated by O. lacteum, whereas the forests in the vicinity of Bykovo and Shelkovichiha with acidic soil reaction (pH_water= 5.68 and 5.42, respectively) and a less developed humus horizon (12.3 cm and 9.9 cm, respectively) are dominated by A. c. caliginosa. The density of E. n. pallida population in small foliage forests is noticeably lower than in pine forests, which cannot be explained by the measured soil characteristics.

Morphometric analysis of E. n. nordenskioldi. This study demonstrated that individuals of E. n. nordenskioldi subspecies of the epi-endogeic earthworms vary markedly in their size: it is visually possible to distinguish between the small-sized and large-sized forms (Fig. 9). The results of morphometric analysis of samples of different-sized earthworms are shown below (Table 7).

Figure 9. Polymorphism of E. n. nordenskioldi
Note: 1 – large-sized, soil; 2 – Kol’covo, deadwood; 3 – Bykovo, deadwood; 4 – Verh-Tula, soil.

Table 7. Morphometric analysis of E. n. nordenskioldi individuals (X ± SE)

Sample No.	Place of sampling	Number of individuals	Number of segments	Body length, mm	Body width, mm	Clitellum length, mm	Clitellum width, mm	Weight, g
Small-sized
1	Verh-Tula, soil	11	114±5	48.7±1.5	2.7±0.1	4.2±0.2	2.9±0.1	0.2±0.01
2	Bykovo, deadwood	20	106±1	53.5±1.0	3.1±0.1	4.4±0.1	3.2±0.1	0.25±0.01
3	Kol’covo, deadwood	17	102±2	61.0±1.7	3.2±0.1	3.7±0.1	3.2±0.1	0.3±0.01
Large-sized
4	Pine forests	9	133±7	114.2±5.6	6.0±0.3	6.7±0.4	4.9±0.2	1.8±0.2
5	Small foliage forests	7	126±5	104.9±3.9	5.2±0.1	6.1±0.2	5.3±0.2	1.5±0.2

The largest number of features (5–6), for which statistically significant differences were revealed, was found when comparing samples of large-sized and small-sized forms of E. n. nordenskioldi. When comparing samples of small-sized forms with each other, we revealed no more than 3 features that show statistically significant differences. Samples of large-sized forms for pine forests and small foliage forests do not significantly differ (Table 8). Therefore, in this paper, we show the population density indicators for both large-sized and small-sized forms of E. n. nordenskioldi separately.

 

Table 8. List of statistically significant differences between samples

(Mann–Whitney U-test, p < 0.01)

Sample No.	2	3	4	5
1	SN, BW, W	SN, BL, BW, W	BL, BW, CL, CW, W	BL, BW, CL, CW, W
2	—	BL, CL, W	SN,  BL, BW, CL, CW, W	SN,  BL, BW, CL, CW, W
3		—	SN,  BL, BW, CL, CW, W	SN,  BL, BW, CL, CW, W

Note: For legend, see Materials and Methods

 

 

DISCUSSION

When studying the polymorphism of E. n. nordenskioldi, it should be noted that the small-sized form mainly inhabits deadwood and is less common in the soil, while the large-sized form lives only in the soil, often at a depth of more than 15–20 cm, although it feeds on the surface. There is an assumption that large-sized individuals belong to the anecic worms. A similar point of view has already been proposed during the research of the forests of the Western Sayan Mountains and the soils of Yakutia (Perel’, 1994; Boeskorov, 2004), where large-sized and small-sized forms of this subspecies were also found, and the large form was characterised as anecic. It should also be mentioned that in the earthworm samples collected by Ju. B. Byzova in birch forests in the vicinity of Novosibirsk, large-sized individuals of E. n. nordenskioldi of a certain size and weight were considered anecic (Byzova, 2007).

Figure 10. Similarity of the external appearance between the large-sized forms of E. n. nordenskioldi (1) and L. terrestris (2)

These statements can be confirmed by the following observation: when comparing the large-sized form of E. n. nordenskioldi with the typical representative of anecic worms L. terrestris, one can note the similarity in their external morphology (Fig. 10). In particular, the large-sized form has a pronounced flattening of the body and a weakening of pigmentation from the head end towards the tail, whereas in small-sized worms there is no pronounced flattening of the body, and the pigmentation of the body is very even. However, it is not yet possible to univocally assert that the large-sized form of E. n. nordenskioldi found in Novosibirsk area can be categorised as anecic; this would require detailed studies of the internal morphology, as well as looking for long vertical passages in the soil, typical of anecic earthworms.

A similar study was conducted for O. lacteum. Novosibirsk area is habitat to large-sized and small-sized forms of this species that have significant differences not only in morphological features, but also at the molecular and genetic level (Shehovcov et al., 2020). The large-sized form of O. lacteum is mainly confined to floodplain biotopes, while in the forests, only the small-sized form is found.

The population of earthworms in pine forests and small foliage forests was generally similar in terms of species composition and the ratio of living forms, but the population density of worms in small foliage forests is much higher than in pine forests. Even in a dry low-grass birch forest (Verh-Tula), the population density was higher than in the most «poorly» populated pine forest (Baryshevo). However, the population of earthworms in tall-herb-fern pine forests is noticeably more diverse than in dark coniferous forests (Geraskina, 2016b) and Southern taiga (Krylova et al., 2011), where there were usually no endogeic earthworms at all, while epigeiс and epi-endogeic earthworms are represented by one species. Birch-aspen forests of the forest-steppe Ob region (Novosibirsk area) have a diverse species composition and high population density of earthworms, which nevertheless is still inferior to small foliage and broad foliage forests in the European part of Russia (Perel’, 1958; Akkumuljacija…, 2018; Geraskina, 2016, 2016а). The main difference between the complexes of living forms of earthworms in Novosibirsk area and the above-mentioned regions is the absence of typical anecic forms (if we don’t consider the large-sized form of E. n. nordenskioldi as one). Anecic earthworms are represented L. terrestris, which is extremely rare here; it inhabits anthropogenic territories and was not found in natural habitats (Ermolov, 2018a, 2019).

In the studied forests, population density of endogeic earthworms is much higher than that of epigeiс and epi-endogeiс earthworms. Most of the population of epigeiс and epi-endogeic earthworms is concentrated in the forest deadwood, earthworms even reproduce there, as evidenced by cocoons found (Geraskina, 2016c; Ermolov, 2018a). Deadwood effectively maintains the diversity of epigeiс and epi-endogeiс earthworms in forest ecosystems. In different habitats, the ratio of epigeiс and epi-endogeiс earthworms in deadwood may differ, but the species composition is almost always similar to that in the soil (Tables 1, 2, 3, and 4). Endogeic earthworms can also be found in deadwood. They mainly inhabit heavily decomposed trunks and are represented by juvenile individuals, which usually live close to the soil surface. Adult individuals are found in deadwood much less often and seem to use it as a temporary habitat; for example, to crawl there after leaving the soil during rain (Chekanovskaja, 1960; Geraskina, 2016c).

It should also be noted that among epigeiс and epi-endogeiс earthworms in the soil, the population density of cosmopolitans (D. r. tenuis, D. octaedra, L. rubellus) and the Asian subspecies (E. n. nordenskioldi) is approximately the same in different habitats, and among the endogeic earthworms, cosmopolitans (O. lacteum, A. c. caliginosa) are much more common than the Asian subspecies E. n. pallida. Some species of epigeiс and epi-endogeiс earthworms are not confined to specific soil factors, and total density of their population directly depends on soil humidity, since these groups live near the very surface of the soil and are therefore more sensitive to drying out (Chekanovskaja, 1960; Perel’, 1979; Geraskina, 2016a). At high humidity, worms of this ecological group are abundant even in acidic soil, especially in small foliage forests (pH_water= 5.42), where the litter is more nutritious than in pine forests (Holdsworth et al., 2008). Nevertheless, epigeiс and epi-endogeiс earthworms have less influence on soil pH, and therefore the correlation between their population density and this factor requires more detailed studies. No direct correlations were found with the litter thickness, but in forests with L. rubellus (Zael’covskij pine forest, Bykovo), the litter thickness was noted to be the smallest, since this species processes litter more intensively than other epigeiс and epi-endogeiс earthworms (Golovanova et al., 2018). There was a correlation between the population density of individual species of endogeic earthworms and soil humidity in pine forests. The negative correlation of A. c. caliginosa population density with soil humidity is probably due to the fact that this subspecies is capable of summer diapause and therefore can better tolerate drought than other earthworm species (Perel’, 1975, 1979). In wetter soils, however, the population density of other species, which may outnumber A. c. caliginosa, increases. No significant correlations were observed in small foliage forests. At the same time, the studied small foliage forests differed greatly in the species composition of endogeic earthworms: in the birch-aspen forest in the vicinity of Morozovo settlement, O. lacteum prevailed, which can be explained by a thick humus horizon and weak soil acidity. This type is usually predominant in waterlogged soils, but as mentioned above, in the small foliage forests of the studied region where soil is too dry, only small-sized O. lacteum individuals are found, whereas more humid habitats (floodplains) are inhabited by the large-sized form of the species (Shehovcov, Ermolov, et al., 2020). It was also found that the size of adult O. lacteum individuals correlates with soil humidity (Ermolov, unpublished data), and a thick humus horizon ensures the presence of this species, since it is its main habitat and food source (Chekanovskaja, 1960; Perel’, 1979). In more acidic, but also more humid habitats, A. c. caliginosa is found, while in dry forests with slightly acidic soil, only E. n. pallida is found, which is apparently able to survive in soils with low moisture content and a shallow humus horizon.

CONCLUSION

In pine forests and small foliage forests of the forest-steppe Ob region of Novosibirsk area, the species composition of earthworms is largely similar, but the total population density of worms is noticeably higher in small foliage forests. In most habitats, a significant proportion of the population consists of middle-soil-layer endogeic earthworms, and only in one case (small foliage forest in the vicinity of Morozovo), upper-soil-layer endogeic earthworms were predominant. Also, in some forests, the proportion of epigeiс and epi-endogeiс earthworms is high.

The deadwood studied in the forests was divided into three groups, depending on the predominant living forms of earthworms. Deadwood was most often dominated by epigeiс earthworms, while in the fewest number of cases endogeic earthworms were present there. But with the same ratio of living forms of earthworms, deadwood within the same group can significantly differ in species composition.

The study confirmed that in forest ecosystems, soil humidity is the most significant factor for earthworms, especially for epigeiс and epi-endogeiс living forms. For the endogeic earthworms, the thickness of the humus horizon is also important.

Morphometric analysis of external morphological features provided rationalization for the identification of large-sized and small-sized forms of the Eisenia n. nordenskioldi subspecies. Small-sized forms of this subspecies are typical epi-endogeic earthworms that inhabit the soil and deadwood. The large-sized form might belong to anecic worms.

The study provides initial data on the population of earthworms in the forest ecosystems of the forest-steppe Ob region of Novosibirsk area. In the future, it is planned to conduct more detailed studies of each type of forest, paying special attention to pine forests and mixed forests, since they are home to earthworm species that have a limited range and are confined exclusively to the Asian part of Russia.

ACKNOWLEDGEMENTS

The author would like to express profound gratitude to the postgraduate student of the Department of General Biology and Ecology of NSU Maria Nikitichna Kim-Kashmenskaja for numerous consultations and support at the main stages of the work; to Professor Mihail Georgievich Sergeev and senior lecturer Vladimir Vladimirovich Molodcov (NSU, Department of General Biology and Ecology) for their mentorship, understanding, assistance in organizing the study, technical and scientific advice on data processing and consulting on organizational issues, as well as to the reviewers for valuable advice and just criticism. The study was conducted within the framework of the state CEPF RAS assignment AAAA-A18-118052590019-7. 

  

REFERENCES

Akkumuljacija ugleroda v lesnyh pochvah i sukcessionnyj status lesov (Carbon accumulation in forest soils and forest succession status), Moscow: Tovarishhestvo nauchnyh izdanij KMK, 2018, 232 p.

Ashwood F., Vanguelova E.I., Benham S., Butt K.R., Developing a systematic sampling method for earthworms in and around deadwood, Forest Ecosystems, 2019, Vol. 6, No. 33, pp. 1-12.

Atlas Novosibirskoj oblasti (Atlas of the Novosibirsk region), Moscow: Roskartografija, 2002, 56 p.

Boeskorov V.S., Ekologicheskie uslovija obitanija dozhdevogo chervja Eisenia nordenskioldi, Eisen v merzlotnyh pochvah Jakutii. Avtoref. diss. kand. biol. Nauk (Ecological conditions of the earthworm Eisenia nordenskioldi, Eisen in permafrost soils of Yakutia. Extended abstract of candidate’s thesis), Ulan-Udje: IOiEB SO RAN, 2004, 24 p.

Byzova Ju.B., Dyhanie pochvennyh bespozvonochnyh (Respiration of soil invertebrates), Moscow: Tovarishhestvo nauchnyh izdanij KMK, 2007, 328 p.

Chekanovskaja O.V., Dozhdevye chervi i pochvoobrazovanie (Earthworms and soil formation), Moscow, Leningrad: Izd-vo AN SSSR, 1960, 208 p.

Ermolov S.A., Faunisticheskoe raznoobrazie i jekologija dozhdevyh chervej v biotopah rechnyh dolin lesostepnogo Priob’ja (Faunal diversity and ecology of earthworms in the biotopes of river valleys in the forest-steppe Ob), 56^th International Scientific Studet’s Conference ISSC 2018, Novosibirsk, 22-27 Aipril 2018, Novosibirsk: 2018, p. 155.

Ermolov S.A., Osobennosti raspredelenija zhiznennyh form dozhdevyh chervej (Lumbricidae) lesostepnogo Priob’ja (Features of distribution of earthworms life forms (Lumbricidae) in the forest-steppe Ob region), Nauchnye osnovy ustojchivogo upravlenija lesami (Scientific foundations of sustainable forest management), Moscow, 30 October-1 November 2018, Moscow: CJePL RAN, 2018a, pp. 43-45.

Ermolov S.A., Biotopicheskoe raspredelenie dozhdevyh chervej (Oligochaeta, Lumbricidae) v malyh rechnyh dolinah lesostepnogo Priob’ja (Biotopical distribution of earthworms (Oligochaeta, Lumbricidae) in small river valleys of the forest-steppe Ob region), Russian Journal of Ecosystem Ecology, 2019, Vol. 4, No. 2, pp. 1-18.

Ganin G.N., Strukturno funkcional’naja organizacija soobshhestv mezopedobiontov juga Dal’nego Vostoka Rossii (Structural and functional organization of mesopedobionts communities in the South of the Russian Far East), Vladivostok: Dal’nauka, 2013, 380 p.

Geraskina A.P., Dozhdevye chervi (Oligochaeta, Lumbricidae) okrestnostej pos. Dombaj Teberdinskogo zapovednika (Severo-zapadnyj Kavkaz, Karachaevo-Cherkessija) (Earthworms (Oligochaeta, Lumbricidae) the surrounding area of the Dombai of the Teberdinsky reserve (North-Western Caucasus, Karachay-Cherkessia), Trudy Zoologicheskogo instituta RAN, 2016, Vol. 320, No. 4, pp. 450-466.

Geraskina A.P., Ekologicheskaja ocenka dinamiki kompleksa dozhdevyh chervej (Lumbricidae) v hode vosstanovitel’nyh sukcessij (Ecologicall assessment of the earthworms (Lumbricidae) complex dynamics in the course of regenerative successions), Smolensk: SGMU, 2016a, 149 p.

Geraskina A.P. The population of earthworms (Lumbricidae) in the main types of dark coniferous forests in Pechora-Ilych Nature Reserve, Biology Bulletin, 2016, Vol. 43, No. 8, pp. 819-830.

Geraskina A.P., Problemy kolichestvennoj ocenki i ucheta faunisticheskogo raznoobrazija dozhdevyh chervej v lesnyh soobshhestvah (Problems of quantification and accounting faunal diversity of earthworms in forest communities), Russian journal of ecosystem ecology, 2016c, Vol. 2, No. 2, pp. 1-9.

Golovanova E.V., Knjazev S.Ju., Karaban K., Est’ li preimushhestva u aborigennogo vida dozhdevyh chervej po sravneniju s vidami vselencami v Zapadnoj Sibiri? (Are there advantages of native species of earthworms compared to the types of the invided species in Western Siberia?), XVIII Vserossijskoe soveshhanie po pochvennoj zoologii (XVIII All-Russia Meeting of Soil Zoology), Moscow, 22-26 October 2018, Moscow: 2018, pp. 60-61.

GOST 28268-89 (Soils. Methods for the determination of moisture, maximum hygroscopic moisture and humidity sustainable wilting plants), Moscow: Standartinform, 2006, 14 p.

Holdsworth A.R., Frelich L.E., Reich P.B., Litter decomposition in earthworm-invaded northern hardwood forests: Role of invasion degree and litter chemistry, Ecoscience, 2008, Vol. 15, No. 4, pp. 536-544.

Kim-Kashmenskaja M.N., Fauna dozhdevyh chervej (Oligichaeta, Lumbricidae) dolina r. Berd’ v Prisalair’e (Fauna of earthworms (Oligochaeta, Lumbricidae) of the Berd river valley in Prisalairye), Bioraznoobrazie: global’nye i regional’nye processy (Biodiversity: Global and Gegional Processes), Ulan-Udje, 23-27 June 2016, Ulan-Udje, 2016, pp. 242-243.

Krylova L.P., Akulova L.I., Dolgin M.M., Dozhdevye chervi (Oligochaeta, Lumbricidae) Taezhnoj zony respubliki Komi (Earthworms (Oligochaeta, Lumbricidae) of the Taiga zone in Komi Republic), Syktyvkar, 2011, 104 p.

Metody pochvenno-zoologicheskih issledovanij (Researching methods of soil zoology), Moscow: Nauka, 1975, 281 p.

Mugako A.L., Priroda Novosibirskoj oblasti (Nature of the Novosibirsk region), Novosibirsk: Novosibirskij gosudarst-vennyj kraevedcheskij muzej, 2008, 40 p.

Musienko I.E., Ocenka vidovogo raznoobrazija semejstva Lumbricidae v Tashtagol’skom rajone Gornoj Shorii (Assessment of the Lumbricidae species diversity in the Tashtagolsky district of Gornaya Shoria), 57^th International Scientific Studet’s Conference ISSC 2019, Novosibirsk, 14-19 Aipril 2019, Novosibirsk: 2019, p. 25.

Penev L.D., Vasil’ev A.I., Golovach S.I., Kvavadze E.Sh., Vdovoj sostav i klassifikacija gruppirovok dozhdevyh chervej (Oligochaeta, Lumbricidae) dubrav russkoj ravniny (Species composition and classification of earthworm groups (Oligochaeta, Lumbricidae) in Russian plain oak forests), Zoologicheskij zhurnal, 1994, Vol. 73, No. 2, pp. 23-37.

Perel’ T.S., Dozhdevye chervi (Oligochaeta, Lumbricidae) v lesah Zapadnogo Sajana (s opisaniem novogo vida) (Earthworms (Oligochaeta, Lumbricidae) in the forests of Western Sayan (with a description of a new species), Zoologicheskij zhurnal, 1994, Vol. 73, No. 2, pp. 18-22.

Perel’ T.S., Rasprostranenie i zakonomernosti raspredelenija dozhdevyh chervej fauny SSSR (Distribution and distribution patterns of earthworms fauna in the USSR), Moscow: Nauka, 1979, 272 p.

Perel’ T.S., Zavisimost’ chislennosti i vidovogo sostava dozhdevyh chervej ot porodnogo sostava lesonasazhdenij (Dependence of the quantity and earthworm’s species composition on the species composition of forest plantations), Zoologicheskij zhurnal, 1958, Vol. 37, No. 9, pp. 1307-1314.

Perel’ T.S., Zhiznenye formy dozhdevyh chervej (Lumbricidae) (Earthworm’s (Lumbricidae) living forms), Zhurnal obshhej biologii, 1975, Vol. 36, No. 2, pp. 189-202.

Pochvennaja karta Novosibirskoj oblasti (Soil map of the Novosibirsk area), Novosibirsk: Izd. IPA SO RAN, 2007.

Rapoport I.B., Sezonnaja aktivnost’ dozhdevyh chervej (Oligochaeta, Lumbricidae) pojasa shirokolistvennyh lesov kabardino-balkarskogo gosudars-tvennogo vysokogornogo zapovednika i prilegajushhih territorij (Central’nyj Kavkaz) (Seasonal activity of earthworms (Oligochaeta, Lumbricidae) in broad-leaved forests belts of the Kabardino-Balkar state high-mountain reserve and adjacent territories (Central Caucasus), Izvestija samarskogo nauchnogo centra Rossijskoj akademii nauk, 2010, Vol. 12, No. 1(5), pp. 1345-1348.

Shashkov M.P., Fauna dozhdevyh chervej (Lumbricidae) zapovednika “Kaluzhskie zaseki” (The earthworms (Lumbricidae) fauna of “Kaluzhskie Zaseki” nature reserve), Trudy gosudarstvennogo prirodnogo zapovednika “Kaluzhskie zaseki”, Issue 1, 2003, pp. 90-93.

Shehovcov S.V., Bazarova N.Je., Berman D.I., Bulahova N.A., Golovanova E.V., Konjaev S.V., Krugova T.M., Ljubechanskij I.I., Pel’tek S.E., DNK-shtrihkodirovanie: skol’ko vidov dozhdevyh chervej zhivet na juge Zapadnoj Sibiri? (DNA barcoding: how many earthworm species live in the South of Western Siberia?), Vavilovskij zhurnal genetiki i selekcii, 2016, Vol. 20, No. 1, pp. 125-130.

Shehovcov S.V., Ermolov S.A., Derzhinskij E.A., Polubojarova T.V., Laricheva M.S., Pel’tek S.E., Geneticheskaja i razmernaja izmenchivost’ Octolasion tyrtaeum (Lumbricidae, Annelida) (The genetic and dimensional variability of Octolasion tyrtaeum (Lumbricidae, Annelida)), Pis’ma v Vavilovskij zhurnal genetiki i selekcii, 2020, Vol. 6, No. 1, pp. 5-9.

Vjen Rajzin Dzh., Klassifikacija i klaster (Classification and cluster), Moscow: Mir, 1980, 390 p.

Vorob’eva L.A., Ladonin D.V., Lopuhina O.V., Rudakova T.A., Kirjushin A.V., Himicheskij analiz pochv. Voprosy i otvety (Chemical analysis of soils. Questions and answers.), Moscow, 2012, 186 p.

Vsevolodova-Perel’ T.S., Dozhdevye chervi fauny Rossii. Kadastr i opredelitel’ (Earthworms of the fauna of Russia. Inventory and identification guide), Moscow: Nauka, 1997, 102 p.

Reviewer: сandidate of Biological Sciences, Senior Research Officer Geraskina A.P.

]]> https://jfsi.ru/4-1-2021-martynenko_et_al/ Sun, 28 Mar 2021 19:00:30 +0000 https://jfsi.ru/?p=4090

Original Russian Text © 2020 O.V. Martynenko, V.N. Karminov, P.V. Ontikov published in Forest Science Issues Vol. 3, No. 2, pp. 1-12

O.V. Martynenko¹*, V.N. Karminov¹^,²^,³, P.V. Ontikov⁴

¹All-Russian Institute of Continuous Education in Forestry (ARICEF)

Insitutskaya st. 20, Pushkino, Moscow region 141200, Russian Federation

²Center for Forest Ecology and Productivity of the Russian Academy of Sciences

Profsoyuznaya st. 84/32 bldg. 14, Moscow 117997, Russian Federation

³Mytischi Branch of Bauman Moscow State Technical University

1st Institutskaya street, 1, Mytischi, Moscow region 141005, Russian Federation

⁴Federal forestry agency FSBI «ROSLESINFORG» «CENTRLESPROEKT»

Zavodskaya st. 10, Ivanteevka, Moscow region 141200, Russian Federation

*E-mail: martinen75@yandex.ru

Received 03.03.2020

Accepted 03.06.2020

The territory of the N.V. Tsitsin Main Botanical Garden of the Russian Academy of Sciences is subjected to significant anthropogenic stress, which has a negative effect on the state of valuable collections of tree and shrub species. Soil compaction is one of the most dangerous consequences of anthropogenic impact, expressed in increased recreational impact. In this context, the botanical garden was very concerned about the deterioration of the collection of elaeagnus species. Therefore, the soils on which these plants grow were chosen as the object of research. On this territory, three sampling plots with different degrees of anthropogenic impact were laid. Sampling plot No. 1 had the maximum anthropogenic impact. The area of medium anthropogenic impact was represented by the sampling plot No. 2. The sampling plot No. 3 where the anthropogenic impact was minimal was a reference plot. All the studied soils were classified as soddy-slightly podzolic medium loamy soils (Umbric Albeluvisols Abruptic). Fundamental differences in the morphological properties of the studied soils were that the soils located in the area of maximum anthropogenic impact, starting from a depth of 40 cm, showed gley spots, which were not found in other soils. Increased bulk density of soil in undisturbed state corresponded to increased anthropogenic impact. This led to a decrease in total pore space of soil. Soil compaction contributed to a noticeable decrease in gravimetric soil water content in upper horizons. At the same time, worsening of subsurface runoff contributed to gley-forming processes in the illuvial part of the profile. Cluster analysis revealed good grouping of the dependence of the studied indicators on the severity of anthropogenic impact. The studied indicators were separated depending on their type and position in the profile. The conducted study made it possible to assess the essential physical and hydrophysical properties of soils on the part of the territory of the Main Botanical garden of RAS that is occupied by the valuable collection of elaeagnus. Based on the results of the study, a set of measures is proposed that can significantly reduce the identified negative effects and improve the state of both the studied soils and stands growing on them in general.  

Key words: bulk density of soil, anthropogenic compaction, soils of botanical gardens, GBS RAS

N.V. Tsitsin Main Botanical Garden of the Russian Academy of Sciences (GBS RAS) can be justly put on the list of the most interesting and well-known botanical gardens in the world. Opened in 1945, it compactly accommodates unique collections of tree and shrub species from all over the world (Demidov et al., 2016). By the decree of the Presidium of the USSR Academy of Sciences on December 2, 1991 the Main Botanical Garden was named after the member of the Academy of Sciences Nikolai Vasilievich Tsitsin.

GBS RAS is the largest botanical garden in Europe. For the convenience of visitors and employees, the botanical garden has an extensive network of asphalt and dirt paths. Such a well-developed trail and path network allows for both easy hikes and active sports including running and cycling. High profile of the botanical garden among Muscovites and metropolitan visitors results into strong anthropogenic impact on its stands and soils (Grevtsova, Rysin, 2020).

The main issue with the soils of recreational areas is their compaction caused by heavy traffic of vehicles, people and animals. Soil compaction decreases the total pore space by 30–50%, primarily due to micropores, which play a central role in the movement of water and air as well as the spread and growth of plant roots. This directly affects the basic hydrophysical properties of the soil: on the one hand, water permeability decreases, and therefore conditions that favour water stagnation are created, which is best seen in illuvial horizons; on the other hand, the compaction of the upper humus horizon reduces the ability of soil to absorb and retain moisture. The negative impact of anthropogenic compaction on the crucial soil properties was reported by many researchers (Smagin et al., 2006; Lysikov, 2006, 2008, 2011; Yakovlev, Evdokimova, 2011; Melankholin, Lysikov, 2014; Stoma, 2016; Zakharov, Kulik, 2017; Murachеva, 2018). It is usually not so much the over-compaction of soil on the paths as the preservation of unique park cenoses, where a variety of vegetation is represented, that causes concern (Mosina, 2003).

It should be noted that some authors consider the soils of botanical gardens some kind of unique formation that differs from both natural and urban green areas and was formed due to constant introduction of soil fauna and microorganisms on plant roots and in soil as well as long-term (for decades and even centuries) anthropogenic (urbanogenic) impact (Rappoport et al., 2013). Thus, urban botanical gardens are unique artificially created ecosystems, where the negative impact of the urban environment is partially offset and there is a high level of biodiversity. This study was performed within that narrative, and the objective of the study was to identify and evaluate the likely impact of the complex of soil factors on the condition of stands (collection of elaeagnus species) of the GBS RAS.

MATERIALS AND METHODS

This research was carried out as part of a comprehensive soil and hydrotechnical survey of the territory of the GBS RAS conducted by the staff and students of Mytishchi branch of N.E. Bauman Moscow State Technical University. Special emphasis was made on looking into the influence of anthropogenic factors on soil properties, which, in turn, largely determine the conditions for the growth and development of tree and shrub species growing in the botanical garden (Rysin, Grevtsova, 2018). According to our tentative hypothesis, it was the anthropogenic compaction that could cause the death of the collection of Elaeagnus. Most likely, the paths made worsened the outflow of groundwater and led to soil waterlogging in the spring.

The study program included laying three sampling plots each 20´20 m of size. Two sampling plots were located directly on the territory of the collection of elaeagnus. Sampling plot No. 1 was laid at a distance of about 10 meters from a busy central pedestrian walkway. This sampling plot represented the part of the territory occupied by the collection of elaeagnus with the highest anthropogenic impact. Stage 4 of recreational degradation was diagnosed for this area. Sampling plot No. 2 was located at a distance of about 20 meters from the central alley, next to a small path, where the anthropogenic impact was moderate. In this zone, recreational degradation was at stage 3. As a reference plot, sampling plot No. 3 was laid down in a relatively inaccessible place, where visitors to the garden do not get very often. The distance from the central pedestrian walkway was about 50 meters. Stage 2 of recreational degradation was stated in this area.

During the field research phase, at each sampling plot 5–6 test pits were made. For each sampling plot, one most typical test pit was deepened to form a section. Thus, section B3 (N55.842984, E37.598317) was located in the area of maximum anthropogenic impact. The area with moderate anthropogenic impact was represented by section B2 (N55.84282, E37.59879), whereas the control section B1 (N55 N55.842588, E37.598169) was laid in the area with low anthropogenic impact. All locations are given in the WGS84 system.

For the soil sections and pits, a complete morphological description was performed according to the methods used in soil science. Samples were taken from all sections on genetic horizons to determine the general physical and hydrophysical properties of soils at the soil laboratory of a department of Mytishchi branch of N.E. Bauman Moscow State Technical University. In particular, bulk density in the undisturbed natural state (according to N.A. Kachinski), field gravimetric soil water content by weight method and the total pore space of soil were determined. Assessment of soil parameters provided results within 5% in terms of accuracy of the experiment at a significance level of 0.05 (Vadyunina, Korchagina, 1986).

The selection of soil sampling points, georeferencing of the sections made, and land navigation were carried out using modern geoinformation systems. For the study, a combination of the NextGIS mobile application for Android and the Quantum GIS desktop application was chosen, the latter was used for combining and systematization of all the obtained geodata. The QGIS system has been an almost absolute leader in recent years in the free software class (Shokin, Potapov, 2015).

The obtained experimental data were processed using multidimensional statistical methods, more specifically, cluster analysis. For the studied objects, dendrograms were constructed, with the values of similarity (or difference) represented on the Y axis, and the numbers of objects with equal intervals represented on the X axis. The normalized Euclidean distance was chosen as a measure of difference: the geometric distance between objects in a multidimensional feature space. For clustering, Ward’s method was used. Analysis of variance method was used in this study to estimate distances between clusters. The distance between clusters is seen as the increase in the sum of squared distances from objects to the centre of the cluster, obtained as a result of their union.

RESULTS AND DISCUSSION

Field studies showed that all the surveyed soils are Umbric Albeluvisols Abruptic (WRB, 2015). The grain size did not change significantly along the profile. Bigger grain size was found only in the lowest part of the profile in the transition horizons to the parent rock.

The main difference in the morphological properties of the studied soils was that in the soils located in the area of maximum anthropogenic impact, starting from a depth of 40 cm there were gley spots which were not found in soils with low and medium anthropogenic impact. The main characteristics of soils are presented in Table 1.

Table 1. Bulk density, total and field gravimetric soil water content

Sequence No.	Severity of anthropogenic impact	Horizon­	Horizon boundaries (thickness), cm	Depth of sampling, cm	Bulk density of soil, g/cm³	Total pore space of soil, %	Field gravimetric soil water content, %
1	maximum	A₁	2…14 (12)	5…15	1.29±0.05	52.16±2.59	36.34±1.88
		А₁А₂	14…29 (15)	18…28	1.60±0.04	40.94±1.76	25.40±1.17
		А₂	29…43 (14)	31…41	1.76±0.05	35.28±0.99	20.48±0.90
		А₂В	43…62 (19)	47…57	1.77±0.05	35.40±1.16	15.94±0.45
		Вg	62…	63…73	2.02±0.05	26.16±1.03	16.66±0.77
2	medium	A₁	1…18 (17)	4…14	1.15±0.04	57.44±1.57	34.24±0.68
		А₁А₂	18…35 (17)	22…32	1.33±0.06	51.10±2.13	28.20±1.38
		А₂	35…43 (8)	35…43	1.61±0.06	40.88±1.22	20.66±1.00
		А₂В	43…61 (18)	48…58	1.66±0.06	38.86±1.38	16.88±0.78
		В	61…	62…72	1.74±0.05	36.02±1.50	18.10±0.90
3	low	A₁	1…24 (23)	5…15	0.97±0.03	64.24±1.68	42.62±1.32
		А₁А₂	24…34 (10)	24…34	1.10±0.05	60.07±1.61	33.12±1.38
		А₂	34…44 (10)	34…44	1.38±0.06	48.98±1.50	22.16±0.99
		А₂В	44…54 (10)	44…54	1.18±0.05	57.23±1.11	22.72±0.89
		В	54…	55…65	1.48±0.06	46.04±1.88	11.78±0.55

Figure 1. Changes in bulk density of soil depending on anthropogenic impact

The lowest bulk density of soil in the undisturbed state is observed in the area of the minimum anthropogenic impact (Fig. 1). This trend is typical for the depth of the studied soil profile. Natural vegetation with a predominance of birch and mixed herbs in the ground cover at 0.97 g/cm³ provided a fairly favourable density of the upper horizon А₁. Density expectedly increases with the depth, reaching a maximum of 1.48 g/cm³ in the B horizon. For the other two sections located in the area of strong anthropogenic impact, the density of the upper horizon А₁ is substantially higher (1.29 g/cm³ and 1.25 g/cm³) near the walkway and the path, respectively. Although there is a walkway surfaced with good asphalt, some visitors still go off the paths, which leads to soil compaction, and the compacting effect reaches a considerable depth and is seen up to and including the illuvial horizon B.

Of course, these density values have a negative impact on both the state of the soil itself and vegetation, but for comparison, it should be noted that in similar studies, soil density figures in the middle of the path were up to 1.8 g/cm³ (Lysikov, 2008, 2017). Thus, the regular network of well-maintained paths of the GBS still takes on the main load.

The above-mentioned increase in soil density in areas with high and medium anthropogenic impact leads to a decrease in its total pore space (Fig. 2), primarily due to the air pore space, but the capillary pore space also decreases.

Figure 2. Changes in total pore space of soil depending on the anthropogenic impact

Due to all this, field gravimetric soil water content of the compacted horizons decreases significantly (Fig. 3). This is especially visible in the section located near the central walkway.

Figure 3. Changes in gravimetric soil water content depending on anthropogenic impact

When looking at the data obtained, one cannot but agree with S.G. Zakharov (2107), who pointed out that in forested landscapes, paths are not an innocent element anymore, but a kind of suffocating network that breaks down the original woodland into increasingly isolated areas with pulsating and expanding patches of soil and vegetation cover degradation.

Increased loss of water from the upper horizon might also be facilitated by the forest live cover which suffers from trampling and therefore has lower species diversity and smaller projective cover than in the area not easily accessible for visitors.

Low water permeability negatively affects the growth and development of plants, increasing the risk of their death from drowning. Most likely, that very reason caused the death of the collection of elaeagnus on the territory of the N.V. Tsitsin GBS RAS. It could have been avoided by timely and appropriate reclamation measures.

According to the cluster analysis, based on all the obtained soil indicators, areas with maximum and medium anthropogenic impact formed specific groups, whereas the territory with a low level of such impact could be separated quite early (Fig. 4).

Figure 4. Dendrogram of the studied objects («Low» – low impact zone, «Med» – medium impact zone, «Max» – maximum impact zone)

Thus, the changes in soil indicators allow us to state that even medium anthropogenic impact significantly affects the state of soil.

Fig. 5 shows the distribution of soil parameters (properties) in a multidimensional space. The figure shows three areas of indicator clustering. The first one is the largest and includes the values of total pore space and gravimetric soil water content of the upper genetic horizons. The second area of grouping located in the centre of the dendrogram included only the values of the bulk density of soil in the undisturbed state. Moreover, a noticeable division into conditionally «upper”, “middle” and «lower» horizons is already observed within this group.

Figure 5. Dendrogram of the properties of genetic horizons of the studied objects (ε – total pore space, dᵥ – bulk density in undisturbed state, W – field gravimetric soil water content)

The last (third) and smallest group included the gravimetric soil water content of the eluvial and illuvial horizons, which may indicate that groundwater and perched water start to play a significant role here.

It should be noted that this method made it possible to present the relationship between the studied indicators and the value of anthropogenic impact in a well-structured fashion, and these results are quite explainable from the perspective of the scientific theory.

Based on the results of the study, some practical guidelines can be formulated to mitigate the observed negative consequences. Reconstruction of the roadway and addition of elements of selective closed material drainage to it can be recommended as first and most transformative measures to control moisture stagnation (caused by over-compaction and disturbance of the subsurface runoff). In areas of the most critical compaction, material or non-material air drainage should be used. Moreover, special emphasis should be made on controlling the flow of visitors using hedges and on the intensification of informational work with the botanical garden visitors.

CONCLUSION

The performed study made it possible to evaluate the most important physical and hydrophysical properties of soils of the part of the Main Botanical Garden RAS, occupied by the collection of elaeagnus and affected by anthropogenic impact of different intensity. A noticeable increase in the bulk density of soil in undisturbed state in the area of medium and maximum anthropogenic impact was found. Consistent with increased density, a decrease in the total pore space and gravimetric soil water content of the studied soils was observed. Cluster analysis showed that, in terms of the totality of the studied indicators, areas with maximum and medium anthropogenic impact are more similar to each other than to the area with low anthropogenic impact. Even the anthropogenic impact that is deemed medium significantly affects all of the most important general physical and hydrophysical properties of soils.

The results of the study will form the basis for the development of detailed practical guidelines aimed at mitigation of the negative effects of human impact on soils of the GBS RAS and these findings will be included into the soil section of the integrated geographic information system of the GBS RAS and can then be used for assessment and monitoring of soils and plants in arboreta and enhance the recreational potential of the territory of the Botanical garden.

REFERENCES

Demidov A.S., Rysin S.L., Kobyakov A.V., Vozmozhnosti ispol’zovaniya GIS-tehnologii v rabote botanicheskikh sadov (Possibilities of using GIS technologies in the work of Botanical gardens), Lesokhozyaistvennaya informatsiya, 2014, No. 4, рр. 68-72.

Demidov A.S., Shustov M.V., Potapova S.A., Sokhranenie raznoobraziya rastitel’nogo mira Rossii v Glavnom botanicheskom sadu im. N.V. Tsitsina (Preserving the diversity of the Russian flora in the main Botanical garden named after N.V. Tsitsin), Sokhranenie raznoobraziya rastitel’nogo mira v botanicheskikh sadakh: traditsii, sovremennost’, perspektivy. Materialy Mezhdunarodnoi konferentsii, posvyashchennoi 70-letiyu Tsentral’nogo sibirskogo botanicheskogo sada (Preserving the Diversity of the Plant World in Botanical Gardens: Traditions, Modernity, Prospects, Proceedings of the International Conference Dedicated to the 70^th Anniversary of Central Siberian Botanical Garden), 2016, рр. 96-98.

Grevtsova V.V., Rysin S.L., O neobkhodimosti sozdaniya tsentra po izucheniyu dubrav na urbanizirovannykh territoriyakh v Glavnom botanicheskom sadu RAN (About the need to create a center for the study of oak forests in urban areas in the Main Botanical Garden of the Russian Academy of Sciences), Nauchnye trudy Cheboksarskogo filiala Glavnogo botanicheskogo sada im. N.V. Tsitsina RAN, 2020, No.15, рр. 120-122.

Lysikov A.B., Izmeneniya pochvenno-ekologicheskikh uslovii v lesnykh biogeotsenozakh pod vliyaniem rekreatsii (Changes in soil and environmental conditions in forest biogeocenoses under the influence of recreation), Aktual’nye problemy lesnogo kompleksa, 2006, No. 13, рр. 79-82.

Lysikov A.B., Izmenenie plotnosti lesnykh pochv pri rekreatsii (Change in forest soil density during recreation), Lesovedenie, 2008, No. 4, рр. 44-49.

Lysikov A.B., Vliyanie rekreatsii na sostoyanie pochv v gorodskikh listvennykh lesakh (The effect of recreation on the state of soils in urban deciduous forests), Lesovedenie, 2011, No. 4, рр. 11-20.

Melankholin P.N., Lysikov A.B., Vliyanie dorozhno-tropinochnoi seti na travyanuyu rastitel’nost’ i pochvy dubovykh lesov Moskvy i blizhnego Podmoskov’ya (The influence of the road-path network on the grassy vegetation and soils of the oak forests of Moscow and the near Moscow region), Lesovedenie, 2014, No. 2, рр. 38-45.

Mosina L.V., Antropogennoe izmenenie lesnykh ekosistem v usloviyakh megapolisa Moskva, avtoreferat dis. … doktora biologicheskih nauk (Anthropogenic change of forest ecosystems under the conditions of the Moscow megacity), Moskow, Moscow Timiryazev Agricultural Academy, 2003, 38 p.

Muracheva L.S., Uplotnenie pochvy kak faktor ekologicheskikh problem parkovykh ekosistem (Soil compaction as a factor in the environmental problems of park ecosystems). Ekologicheskie problemy prirodnykh i urbanizirovannykh territorii. Materialy IX Mezhdunarodnoi nauchno-prakticheskoi konferentsii (Ecological Problems of Natural and Urbanised Territories. Proceedings of the 19^th International Scientific and Practical Conference), 2018, рр. 85-89.

Rappoport A.V., Lysak L.V., Marfenina O.E., Rakhleeva A.A., Stroganova M.N., Terekhova V.A., Makarova N.V., Aktual’nost’ provedeniya pochvenno-ekologicheskikh issledovanii v botanicheskikh sadakh (na primere Moskvy i Sankt-Peterburga) (Relevance of soil and environmental research in Botanical gardens (on the example of Moscow and St. Petersburg)), Byulleten’Oobshchestva ispytatelei prirody (MOIP), 2013, Vol. 118, Issue 5, рр. 45-56.

Rysin S.L., Grevtsova V.V., Problemy sohraneniya zapovednoi dubravy na territorii GBS RAN (Problems of conservation of protected oak grove on the territory of the GBS RAS). Sbornik materialov XX Mezhdunarodnogo nauchno-prakticheskogo foruma “Problemy ozeleneniya krupnykh gorodov” Sbornik materialov foruma v ramkah Mezhdunarodnoj vystavki “Tsvety – 2018” (Proc. of the XX International scientific and practical forum «Problems of Greening of Large Cities»), 2018, рр. 123-126.

Rysin S.L., Plotnikova L.S., Trusov N.A., Yatsenko I.O., Novye podkhody k organizatsii monitoringa sostoyaniya rastenii v dendrologicheskikh kollektsiyakh (New approaches to monitoring the state of plants in dendrological collections), Byulleten’ Glavnogo botanicheskogo sada, 2015, No. 2, рр. 15-22.

Rysin S.L., Trusov N.A., Yatsenko I.O., Osobennosti organizatsii monitoringa tsennyh drevesnyh rastenii na urbanizirovannykh territoriyakh (Features of monitoring valuable woody plants in urban areas), Vestnik Moskovskogo gosudarstvennogo universiteta lesa – Lesnoi vestnik, 2015, Vol. 19, No. 5, рр. 140-144.

Shokin Yu.I., Potapov V.P., GIS segodnya: sostoyanie, perspektivy, resheniya (GIS today: state, prospects, solutions), Vychislitel’nye tekhnologii, 2015, No. 5, рр. 175-213.

Smagin A.V., Azovtseva N.A., Smagina M.V., Stepanov A.L., Myagkova A.D., Kurbatova A.S., Nekotorye kriterii i metody otsenki ekologicheskogo sostoyaniya pochv v svyazi s ozeleneniem gorodskikh territorii (Some criteria and methods for assessing the ecological state of soils in connection with the greening of urban areas), Pochvovedenie, 2006, No. 5, рр. 603-615.

Stoma G.V., Ekologicheskoe sostoyanie pochv i drevesnykh nasazhdenii selitebnykh landshaftov g. Moskvy (The ecological state of soils and tree plantings of residential landscapes in Moscow), Vestnik Moskovskogo universiteta, 17: Pochvovedenie, 2016, No. 1, pp. 41-48.

Vadyunina A.F., Korchagina Z.A., Metody issledovaniya fizicheskikh svoistv pochv (Methods for studying the physical properties of soils), Moscow: Agropromizdat, 1986, 416 p.

Yakovlev A.S., Evdokimova M.V., Ekologicheskoe normirovanie pochv i upravlenie ikh kachestvom (Environmental regulation of soils and their quality management), Pochvovedenie, 2011, No. 5, рр. 582-596.

Zakharov S.G., Kulik I.V., Tropa i rekreatsionnaya nagruzka: novyi metod opredeleniya uplotneniya pochv na tropakh (Trail and recreational impact: a new method for determining soil compaction on trails), Geograficheskii vestnik, 2017, No. 2, рр. 109-117.

WRB: World Reference Base for Soil Resources, International soil classification system for naming soils and creating legends for soil maps. World Soil Resources Reports, IUSS Working Group. Rome: FAO, 2015, 203 p.

 

 

Reviewer: candidate of Biological Sciences, Associa

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