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COMPARATIVE ANALYSIS OF VEGETATION STRUCTURE IN MOUNTAIN FOREST ECOSYSTEMS OF NORTHERN MONGOLIA (BASED ON THE MODEL POLYGONS)

Ecology and dynamics Опубликовано автором

Petukhov I.A., Andreev A.V., Bazha S.N., Bogdanov E.A., Danzhalova E.V., Drobyshev Yu.I., Rupyshev Yu.A., Khadbaatar S. Comparative Analysis of Vegetation Structure in Mountain Forest Ecosystems of Northern Mongolia (Based on the Model Polygons) // Ecosystems: ecology and dynamics. No 4. 2025. P. 5-62. | Abstract | PDF | Reference

 

 

In this research we conducted large-scale mapping (1:10,000-1:50,000) and description of natural ecosystems at the junction of two belts, forest and forest-steppe mountain, in the Selenga River Basin, Northern Mongolia. Part of broader studies on the forest growth conditions of the Lake Baikal Basin, this research took place in 2019 and 2022 across 4 model polygons: Zelter in the eastern Dzhida Range, Chandmani-Under in the central Eastern Khuvsgul Region, Zunkhara in the foothills of Western Khentii Highlands, and Selbe in the southwestern Khentii Upland.

“Selbe” and “Chandmani-Under” encompass 3 forest vegetation altitudinal belts: mountain-taiga, sub-taiga, and forest-steppe. The low-mountain “Zelter” and “Zunkhara” lack the mountain-taiga belt. Distinctively, unlike most mountain forest areas in Mongolia where only 1-2 coniferous species typically form the primary forest stands, the indigenous forest types in the upper Selbe River Basin are comprised of 4 coniferous species: Pinus sibirica, Larix sibirica, Pinus sylvestris and Picea obovata. In “Chandmani-Under” and “Zelter”, Larix sibirica is the dominant coniferous species, while in “Zunkhara” it is Pinus sylvestris and Larix sibirica.

The large-scale mapping data from the model polygons clearly demonstrated a regular altitudinal succession of altitudinal belts, transitioning from mountain-taiga forests at higher elevations of middle-mountain slopes, through sub-taiga, to forest-steppe communities bordering the steppe belt. As aridity increases from north to south, the lower boundaries of these altitudinal belts, including forest vegetation zones, shift upwards. For instance, taiga forests on north-facing slopes of “Selbe” are located above 1600 m a.s.l. (and above 1650 m on the south-facing slopes), whereas in “Chandmani-Under”, situated over 200 km further north, such forests descend steep north-facing slopes to below 1250 m.

The forest-covered area of the model polygons exceeds 70%. However, there is a significant proportion of secondary pyrogenic small-leaved forests, primarily dominated by Betula pendula subsp. mandshurica and Populus tremula. These secondary birch stands and early-stage post-fire successional forests account for 20-24% of the total forest area in “Selbe” and “Chandmani-Under”, over 50% in “Zelter”, and as high as 98% in “Zunkhara”, where indigenous mountain pine-larch and larch-pine sub-taiga forests are entirely absent.

Analysis of the maps depicting forest ecosystems with destroyed indigenous stands at various stages of recovery, alongside their legends characterizing topo-ecological development conditions, enables an assessment of forest degradation scales. This provides a basis for determining natural and technical restoration possibilities, methods, and volumes, and for selecting the most suitable forest cultures for restoration based on the dominant species in the original stands.

Funding. This work was carried out within the framework of the scientific program of the Joint Russian-Mongolian Integrated Biological Expedition of the Russian Academy of Sciences and the Mongolian Academy of Sciences, and the state task of the Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, topic No. FFER-2024-0025 “Biogeocenology and Ecosystem Evolution”.

Keywords: mountain forest ecosystems, topo-ecological conditions, altitudinal belts, forest-forming species, secondary stands, large-scale mapping.

DOI: 10.24412/2542-2006-2025-4-5-62

EDN: ADAUJU

GEOECOLOGICAL ASSESSMENT OF AQUATIC ECOSYSTEM COMPONENTS OF THE KHODTSA RIVER IN THE MOSCOW REGION UNDER ANTHROPOGENIC LOAD

Ecology and dynamics Опубликовано автором

Zamana S.P., Zubkova V.M., Makakhanyuk Zh.S. Geoecological Assessment of Aquatic Ecosystem Components of the Khodtsa River in the Moscow Region under Anthropogenic Load // Ecosystems: ecology and dynamics. No 4. 2025. P. 63-104. | Abstract | PDF | Reference

 

Presently, small rivers are under a extreme anthropogenic load, especially in regions with many industrial enterprises and high population density. Therefore, their abiotic and biotic components undergo negative changes, which makes a geo-ecological assessment of the aquatic ecosystem of one of them, such as the Khodtsa River in the Moscow Region (its source is at Elektrostal, and its mouth is at Pavlovsky Posad), quite relevant. We addressed the following objectives: determining pollutants in water, snow, coastal soil, bottom sediments, higher aquatic vegetation, and fish, as well as assessing bioindicators, the bioproductivity of higher aquatic vegetation, and environmental risk zones in different sections of the river.

We based our research on the data from field studies conducted in 2017-2023 at various sections of the Khodtsa River, and from laboratory studies. The general methodology included sampling water, snow, coastal soil, bottom sediments, and plants at 3 locations: source of the river, intermediate point, and mouth of the river. Standard methods from the Register of Quantitative Chemical Analysis were used for sample analysis. Currently, quantitative assessment of the risk of ecosystem deterioration is primarily based on the level of pollutant concentration exceeding the established standard in a specific component. However, when addressing environmental issues related to chemical pollution, it is important to consider the response of living organisms to pollution using bioindication and biotesting. Since abiotic components such as water, bottom sediments, and coastal soil in an aquatic ecosystem determine the most important processes that influence the functioning of biotic components (i.e., all living organisms), we used an ecosystem approach based on a comprehensive quantitative study of the migration of priority toxic elements in all links of the biogeochemical food chain of the Khodtsa River aquatic ecosystem.

Our studies of the river’s aquatic ecosystem revealed patterns of heavy metal migration in the “water – bottom sediment – coastal soil – plants – fish” system. Iron, cadmium, lead, ammonium nitrogen, and petroleum products were the predominant pollutants at various sampling sites along the river. Compared to the coastal soil, the bottom sediments were significantly more contaminated with heavy metals at the source and intermediate points. Spatial variability of heavy metal content in sedge (Carex aquatilis) was revealed, depending on their content in water and bottom sediments. Moreover, an acropetal pattern of heavy metal distribution in plants was observed: roots accumulated 7-24 times more Cd, 2-4 times more Pb, and 112-251 times more Fe than shoots. Therefore, to determine the pollution of the aquatic ecosystem with heavy metals, we recommend using sedge (especially its roots) as a bioindicator, which can also be used for phytoremediation of small rivers. The biological productivity of higher aquatic vegetation increased from the source to the mouth of the Khodtsa River.

A complex pattern of heavy metal accumulation in the muscle tissue of the studied fish species such as Amur sleeper and common roach was revealed. During a comprehensive assessment of the pollution of abiotic and biotic components, zonation of the river was carried out. The Khodtsa River is characterized by predominant chemical pollutants (heavy metals, petroleum products, ammonia nitrogen). Zones of increased environmental risk were identified at the source and intermediate point, indicating a significant contribution to pollution from municipal and industrial discharges from Elektrostal. However, later in 2023 monitoring of the coastal soil using the lettuce as a test object revealed that the heavy metal content at the intermediate point was higher than at the river’s source, which is explained by a significantly reduced pollutant input from Elektrostal enterprises. Therefore, for the most rapid and cost-effective assessment of river pollution by heavy metals, phytotoxicity testing of coastal soil using the lettuce as a test object should be used for monitoring.

Keywords: ecosystem approach, water, bottom sediments, coastal soil, water sedge, fish, heavy metals, bioindicators, phytotoxicity, river zonation.

DOI: 10.24412/2542-2006-2025-4-63-104

EDN: CYWCLE

TRANSFORMATION OF PHYTOCENOSES WITH HERACLEUM SOSNOWSKYI (APIACEAE) IN THE «BITZEVSKY FOREST» NATURAL PARK (MOSCOW)

Ecology and dynamics Опубликовано автором

Shvetsov A.N., Shaikina M.N., Kuklina A.G. Transformation of Phytocenoses with Heracleum Sosnowskyi (Apiaceae) in the “Bitzevsky Les” Natural Park (Moscow) // Ecosystems: ecology and dynamics. No 4. 2025. P. 105-124. | Abstract | PDF | Reference

 

The spread rate of the invasive species Heracleum sosnowskyi Manden. (Apiaceae) was analyzed in 2006-2020 using satellite monitoring, and the boundaries of its distribution were determined in the test area of the “Bitsevsky Les” Nature and History Park (Moscow, Russia). The current state of rare and protected plant species in the surveyed area was assessed. Geobotanical surveys were conducted using traditional methods, and the locations of protected and invasive species were recorded. According to the surveys of 2024-2025, in total 17 rare species from the “Red Data Book of Moscow” (2022) were identified: Anthemis tinctoria, Campanula patula, C. persicifolia, C. trachelium, C. latifolia, Corryganthe flos-cuculi, Gentiana cruciata, Dactylorhiza fuchsii, Listera ovata, Neottia nidus-avis, Platanthera bifolia, Primula veris, Lathyrus vernus, Polygonum bistorta, Polygonatum multiflorum, Steris viscaria, Iris pseudacorus. Additionally, 7 species in need of monitoring were found: Convallaria majalis, Leucanthemum vulgare, Maianthemum bifolium, Origanum vulgare, Orthilia secunda, Valeriana officinalis, Viola canina.

The termination of agricultural activities in the territory has triggered recovery successions that are followed by an increasing number of some rare plants. At the same time, Heracleum sosnowskyi continues to spread, changing the structure of the vegetation cover, slowing down the recovery processes, and worsening the species composition of the emerging phytocenoses.

Keywords: satellite monitoring, Heracleum sosnowskyi, plant communities, rare species, Moscow.

DOI: 10.24412/2542-2006-2025-4-105-124

EDN: KYXHWV

AVIFAUNA BIODIVERSITY IN SOME RESERVOIRS OF KALMYKIA UNDER THE MODERN CLIMATE CHANGE AND INCREASING ANTHROPOGENIC LOAD

Ecology and dynamics Опубликовано автором

Shapovalova I.B. Avifauna Biodiversity in Some Reservoirs of Kalmykia under the Modern Climate Change and Increasing Anthropogenic Load // Ecosystems: ecology and dynamics. No 4. 2025. P. 125-145. | Abstract | PDF | Reference

 

 

In this paper, we examine the state of avifauna of several wastewater and drainage water reservoirs, as well as man-made reservoirs of the Republic of Kalmykia, in 2025. We studied the composition and structure of the coastal bird communities of Lake Manych-Gudilo, Lake Ded-Khulsun, and the Chogray Reservoir, as well as several smaller reservoirs of local significance, since they are considered key bird areas of Russia. The water of some of these reservoirs, such as Manych-Gudilo and Ded-Khulsun, are specially protected natural areas of federal and regional significance, which facilitates their monitoring. We provided a current assessment of the diversity of the avifauna and bird populations of these reservoirs and their shores, including species composition, abundance, and abundance indicators. We also assessed the contribution of these reservoirs to the conservation and enrichment of regional biodiversity. We then made recommendations for managing their hydrological regime to maintain and preserve coastal ecosystems, including populations of rare and vulnerable bird species.

Acknowledgments. The author thanks the editor-in-chief and reviewers of “Arid Ecosystems” for their help with preparation of this article for publication; additionally, the author thanks Zh.V. Kuzmina and E.I. Tobolova.

Funding. This work was carried out for the research project of the Water Problems Institute of the Russian Academy of Sciences for 2025-2027, “Study of Surface and Groundwater Quality Formation Processes, Natural and Anthropogenic Mechanisms of Change in the Ecological Status of Water Bodies, Development of Methods and Technologies for Water Resources and Water Quality Management” (No. FMWZ-2025-0002), state registration No. 125030703344-8.

Keywords: steppe zone, desert zone, water reservoir, aridization, hydrological regime, climate, ecosystem, ornithocomplexes, bird population, rare bird species, key ornithological areas, specially protected natural areas, Red Data Book, risk of species extinction, factors affecting populations of near-water bird species, anthropogenic impact.

DOI: 10.24412/2542-2006-2025-4-125-145

EDN: MXHPLU

GALINA OGUREEVA, AN OUTSTANDING RUSSIAN SCIENTIST: GEOGRAPHER, BIOGEOGRAPHER, ECOLOGIST

Ecology and dynamics Опубликовано автором

Miklyaeva I.M., Bocharnikov M.V., Kadetov N.G., Leonova N.B. Galina Ogureeva, an Outstanding Russian Scientist: Geographer, Biogeographer, Ecologist // Ecosystems: ecology and dynamics. No 3. 2025. P. 5-77. | Abstract | PDF | Reference

 

Galina Nikolaevna Ogureeva is a well-known Russian scientist, biological and botanical geographer, and ecologist. She is a Doctor of Geographical Sciences, professor in M.V. Lomonosov Moscow University, and one of the founders of the scientific biogeographical school of Moscow University. Her contribution to the development of biogeographical and bioecological mapping, botanical and geographical zoning has received wide recognition in Russia and abroad, and a large number of her works devoted to mountain biogeography, geography of biodiversity, and a biome concept are reflected in more than 260 publications, including articles in both Russian and foreign scientific journals, monographs, textbooks and teaching aids, popular science publications, maps in numerous atlases.

Galina Nikolaevna Ogureeva is an outstanding teacher. She has developed and then taught courses for a number of biogeographical disciplines that are in demand at Moscow University and in many other Russian and foreign universities. She has helped several generations of students, postgraduates, and candidates of sciences, who then continued to work in Russian and foreign institutes and universities. Today, she continues her active and fruitful scientific and pedagogical work.

Keywords: creative path, expeditions, scientific research and educational process, selected publications.

DOI: 10.24412/2542-2006-2025-3-5-77

EDN: EIWCEP

SALINE SOILS OF RUSSIA (HISTORY OF STUDY, DISTRIBUTION AND GENESIS)

Ecology and dynamics Опубликовано автором

Chernousenko G.I., Pankova E.I., Khitrov N.B. Saline Soils of Russia (History of Study, Distribution and Genesis) // Ecosystems: ecology and dynamics. No 3. 2025. P. 78-113. | Abstract | PDF | Reference

 

 

In this article we have summarized the studies on the distribution and genesis of saline soils in Russia from the early 20th century to the present. Emphasis is placed on the ones carried out by the V.V. Dokuchaev Soil Science Institute, which will celebrate its 100th anniversary in 2027. Maps of the distribution of saline soils of varying chemistry across Russia are analyzed. The factors, sources, and mechanisms of soil salinization in different regions of the country are considered. Brief information is provided on the types of saline and solonetzic soils in all administrative units of the country where they occur, their areas, predominant degrees, depths, and chemistry, as well as the genesis of salinization. The largest areas of saline and solonetzic soils are found in southern Russia, due to a combination of an arid climate, poor drainage, and the presence of saline rocks. This determines the predominantly chloride salinization of the soils of the Caspian Lowland. Further north in the Volga Federal District, the area of saline soils decreases, with chloride-sulfate salinization becoming predominantly present. Gypsum appears, and, more often in solonetzic and irrigated soils, soda also appears. Saline soils form underlain by saline loess-like loams and clays or at close proximity to mineralized groundwater. In the Central Federal District, saline soils are localized, as the area is better drained, and the soil moisture index is close to 1. They are primarily found in the south and southeast of the district. At higher elevations, sulfate-based saline soils develop on saline rocks and where mineralized groundwater approaches, while soda-based salinization is more common in the lowlands. Significantly fewer saline soils are found in the Northwestern Federal District, where saline soils are confined to the coast, forming under the influence of the sea and on marine saline sediments. This determines the predominantly sulfate-chloride and chloride types of salinization of coastal soils. Saline soils are found in the steppe and forest-steppe zones and in the Ural Federal District. In addition to climate, salinization is facilitated by outcrops of saline, often gypsum-bearing, rocks and a loamy soil texture. The chemistry of salinization is predominantly sulfate. Saline soils of the Siberian Federal District are divided into two sharply distinct regions. The western part of the district, which belongs to the West Siberian Plain, is where solonetz and solonetzic soils most often form, with soda chemistry dominating; the salinization type is continental, associated with climate and poor drainage of the territory. The eastern part of the district is characterized by smaller areas of saline soils; solonetz is extremely rare, and the chemistry is predominantly sulfate. Salinization is determined by gypsum-bearing saline deposits and the waters that erode them, including groundwater. Lake Baikal separates the soils of different salinization types. West of Lake Baikal, sulfate salinization clearly predominates, while to the east, a significant proportion of soils exhibit soda salinization, which is prevalent in eastern Transbaikalia. The causes of salinization in Transbaikalia are similar to those in Western Siberia. Both regions lack saline rocks, gypsum, and salt deposits; salinization is primarily continental in origin, and soda-based chemistry or soda-based chemistry predominates. The chemistry and causes of salinization in the soils of the Far Eastern Federal District are different. In the Lena Valley, in the absence of saline rocks or deposits, sulfate-chloride and chloride-saline soils form under permafrost conditions. Permafrost prevents chloride salts from leaching from the profile. In northern Yakutia, Chukotka, and on the country’s eastern coast, predominantly chloride salinization is determined by proximity to the sea and the presence of marine sediments. In Kamchatka, in a zone of increased seismic and volcanic activity, the presence of saline soils is determined by hydrothermal systems, leading to the formation of alum-type salinization.

Keywords: soil salinization maps of Russia, salt accumulation factors, chemistry, depth, degree of salinization, salt genesis, areas of saline soils, administrative units of the Russian Federation.

DOI: 10.24412/2542-2006-2025-3-78-113

EDN: IJHMMC

PREDICTIVE ASSESSMENTS OF THE IMPACT OF MODERN GLOBAL WARMING ON THE LANDSCAPE-ZONAL CONDITIONS OF THE VOLGA RIVER BASIN

Ecology and dynamics Опубликовано автором

Kolomyts E.G. Predictive Assessments of the Impact of modern global Warming of the Landscape-zonal Conditions of the Volga River Basin // Ecosystems: ecology and dynamics. No 3. 2025. P. 114-135. | Abstract | PDF | Reference

Prognostic landscape-ecological scenarios of the nearest future of biosphere have been considered for the first time by the example of a large region, such as the basin of the Volga River. The analysis was based on a method of regional landscape-ecological prognosis, developed by the author, using the methods of discrete mathematics. The analytic and cartographic models of future landscape-ecological conditions were obtained for 2050, 2075 and 2100. The mechanisms of shifts in the mosaic structure of vegetation, soils and landscapes have been revealed on the model territory under different scenarios of disturbing influence of climatic system, which are anticipated in the foreseeable future, i.e., before the end of XXI century. Forthcoming warming caused by human activities and accompanied by the superfluous increase of the surface river flow will occur at the expense of the relative decrease of evapotranspiration, especially, of the groundwater flow. A progressively increasing thermo-arid bioclimatic trend has been predicted, with a general shift of zonal boundaries to the north and with the corresponding changes in the water regime of soils and plant cover structure of the territory. The prognostic models showed the convergence of phytocoenoses into new zonal types of vegetation.

Keywords: global warming, Volga River basin, water balance, vegetation cover, nature zonality, empirical-statistical modeling, regional landscape-ecological prognoses.

DOI: 10.24412/2542-2006-2025-3-114-135

EDN: IKDWFM

REVIEW OF SOILSALINIZATIONINTHE RUSSIAN NORTH FOR THE PERIOD OF 1933-2024

Ecology and dynamics Опубликовано автором

Chernousenko G.I. Review of Soil Salinization in the Russian North for the Period of 1933-2024  // Ecosystems: ecology and dynamics. No 2. 2025. P. 43-78. | Abstract | PDF | Reference

 

 

In this article the works on the soil salinization of the Arctic coast, adjacent subarctic regions of Russia and the Arctic Oceanislands are summarizes, and the definitions of saline soils and saline grounds are explained. Additionally, the distribution and types of frozen saline rocks in coastal zones, sources of salts and factors that determine the specifics of soil formation, including salinization methods and processes (such as leaching of rocks, exchange reactions, desulfation, freezing/thawing), are considered. The existing classifications of coastal soils are analyzed. The distribution, chemistry and degree of soil salinization are studiedusingthe analytical data: starting from the coast of the White Sea and the Ainov Islands of the Barents Sea in the west, to the Chukchi coast and Wrangel Island in the east. Salinization was registered on the coast of the White, Barents, Kara, East Siberian and Laptev Seas, on the Yugorsk and the Yamal Peninsulas, on Vaygach, Sharapovy Koshki, Bolshevik, Bolshoy and Maly Lyakhovsky, Faddeyevsky, Wrangel, Dunay islands, and the Severnaya Zemlya archipelago. The chemistry of soil salinization was thoroughly considered to find out that chloride-sodium chemistry dominates closer to the sea, in the peat soils and soils with a heavier granulometric composition. Meanwhile, on lighter rocks further from the coast, as well as inthe soils on marine terraceswith mobile chlorides washed out from the profile, sulfates begin to predominate, and their chemistry is mostly chloride-sulfate, sometimes with gypsum. In soils with gypsum, the proportion of magnesium is higher, or even dominant in some cases. Soil salinization varies from weak to solonchaks. The ongoing climate aridization will eventually redistributethe saline territories and, possibly, reduce their area due to permafrost degradation and a probable increase in precipitation. Aridization of the northern regions might change the dominant chemistry of salinization, meaning that the predominantly chloride type will most likelychange to chloride-sulfate or sulfate magnesium-sodium.

Keywords: chemistry, degree of salinization, genesis of salts, analytical data, climate change.

DOI: 10.24412/2542-2006-2025-2-43-78

EDN: BLLZXW

EMPIRICAL-SIMULATION PREDICTIVE MODELING OF FOREST ECOSYSTEMS IN THEIR CLIMATOGENIC MONITORING

Ecology and dynamics Опубликовано автором

Kolomyts E.G. Empirical-simulation Predictive Modeling of Forest Ecosystems in Their Climatogenic Monitoring // Ecosystems: ecology and dynamics. No 2. 2025. P. 79-104. | Abstract | PDF | Reference

The article presents a strategy for studying the mechanisms of functional and structural organization of forest ecosystems as objects of terrestrial geosystem monitoring. The spatial-functional monitoring of forests is based on empirically established local and regional landscape-ecological connections, which are considered as mechanisms of metabolic reactions of forest ecosystems to certain climatic trends. This is the novelty of the basic and predictive empirical-simulation concept of regional and local geoecological monitoring developed by the author. Ordination analysis of landscape connections is aimed at identifying transitions of forest communities to critical states according to the main discrete parameters of biological circulation. Catenary landscape-ecological structures that form regional systems of localized natural zonality are capable of imitating the main directions and scales of geosystemic restructurings. Landscape-ecological forecasting is experimental in nature. It is presented as a system of operations with ecological (hydrothermal) niches of the objects under study. In calculation models, the course of predicted processes is reproduced using their empirical imitation by spatially distributed parameters of basic ecological niches. The description of future states of biogeocoenotic systems is carried out according to their current spatial organization in accordance with the fundamental properties of ergodicity of the natural environment. The ambiguous nature of the transformation of forest topogeosystems is revealed at a fixed value of the regional geophysical trend, when their new state can have features of not one, but several basic states. A working algorithm for predictive landscape-ecological calculations is presented. Based on geoecological forecasts, the problem of regulating the quality of the natural environment under global climate change through carbon balances and the functional stability of forest ecosystems is covered.

Keywords: climate change, forest ecosystems, geoecological monitoring, empirical-statistical modeling, ordination analysis, empirical simulation of regional climatic trends, polyzonality of biogeocoenological systems, landscape-ecological forecasting.

DOI: 10.24412/2542-2006-2025-2-79-103

EDN: TXDHTT

POPULATION INDICES AND FAUNA COMPOSITION OF SMALL MAMMALS IN THE ZEYA NATURE RESERVE AND ITS ADJACENT TERRITORIES UNDER THE INFLUENCE OF NATURE AND HYDRAULIC CONSTRUCTION

Ecology and dynamics Опубликовано автором

Podolsky S.A., Levik L.Yu., Pavlova K.P., Chemirskaya D.S., Chervova  L.V. Population Indices and Fauna Composition of Small Mammals in the Zeya Nature Reserve and Its Adjacent Territories under the Influence of Nature and Hydraulic Construction // Ecosystems: ecology and dynamics. No 2. 2025. P. 105-130. | Abstract | PDF | Reference

 

The construction of large water reservoirs in the Amur Region causes numerous negative environmental consequences, changing the boundaries of species’ ranges, as well as reducing the species diversity in zoocomplexes and the number of many animal species. In addition, populations and communities under the influence of reservoirs continue to experience fluctuations due to natural processes. A reliable group of indicators for studying the impact of hydroelectric construction on terrestrial animals are small mammals, such as Rodentia and Eulipotyphla, most of which undergo frequent generational changes and, therefore, have a quick response to changes in their habitats.

In this article, we consider the main natural factors influencing the dynamics of the number of Rodentia and Eulipotyphla in the Zeya Nature Reserve, as well as changes in the abundance and fauna composition of small mammal communities on the shores of the Zeya Water Reservoir and in the influence zone of the Lower Zeya Hydroelectric Complex which is currently under construction. In the reserve and on the reservoir shores, we discovered 16 Rodentia species and 6 Eulipotyphla species. The dynamics of Rodentia number was studied on the basis of data obtained in 1982-2024, namely, from the censuses conducted on 27 trap-lines, with a total volume of about 48.5 thousand spring-loaded bar trap-days. The dynamics of Eulipotyphla was studied on the basis of data from 2003-2024, i.e., the censuses conducted on 8 trap-lines, with a total volume of about 22.9 thousand pitfall trap-days. In the reserve, we picked a zone on the mountainous shores for experimental observations, and another one that included low mountains outside the shores for background observations,

The main impact factors of the hydroelectric construction on the marginal and rare species of small mammals in the upper pool of the Zeya Reservoir are the flooding of valley habitats and the isolation of small groups of animals in the remaining habitats in the estuary areas of the valleys of the reservoir’s tributaries. Due to that the fauna of Rodentia and Eulipotyphla is already significantly depleted on the shores. The following species have disappeared from the area almost entirely: long-tailed ground squirrel (Urocitellus undulatus Pallas, 1779), reed vole (Alexandromys fortis Buchner, 1889), Amur lemming (Lemmus lemmus amurensis Vinogradov, 1924), slender shrew (Sorex gracillimus Thomas, 1907), Eurasian least shrew (Sorex minutissimus Zimmermann, 1780). Meanwhile, such species as the Maximowicz’s vole (Alexandromys maximowiczii Schrenk, 1859), tundra vole (Alexandromys oeconomus Pallas, 1776), striped field mouse (Apodemus agrarius Pallas, 1771), harvest mouse (Micromys minutus Pallas, 1771), flat-skulled shrew (Sorex roboratus Hollister, 1913), and Siberian large-toothed shrew (Sorex daphaenodon Thomas, 1907) changed their “common” or “numerous” status to “very rare”. Similar changes should be expected to occur on the shores of the Nizhne-Zeyskoye Reservoir, which is currently under construction.

The most significant influence factor of a large reservoir on the background species, such as the northern red-backed vole (Myodes rutilus Pallas, 1779), grey red-backed vole (Craseomys rufocanus Sundevall, 1846), and Laxmann’s shrew (Sorex caecutiens Laxmann, 1788), is its climate impact on the biotopes of the shores. It occurs at the same time with the natural number fluctuations of small mammals associated with the main abiotic natural factors, e.g., solar activity, precipitation and temperatures during the period of most active reproduction and the beginning of vegetation (May-June), as well as with the depth of snow cover. Both Rodentia and Eulipotyphla have an inverse correlation between the population dynamic and the amount of precipitation in May-June, as well as a direct correlation between the population dynamic and average temperatures in May-June. At the same time, for the influence zone of the Zeya Reservoir, a close and direct connection has been established between long-term changes in solar activity and precipitation in May-June.

Aside from short 3-4-year fluctuations, Rodentia species go through a long, almost 30-year-long cycle, occurring in an antiphase with similar fluctuations of the Wolf number curve; the population dynamic of Eulipotyphla is in an antiphase with 10-11-year-long cycles of solar activity.

The coasts of the Zeya Reservoir, we have discovered the deepest depressions and maximum amplitudes of population fluctuations both for Rodentia and Eulipotyphla. Moreover, shores such as these tend to become a zone of low abundance of small mammals. In Zeya, average annual losses compared to the background indicators are 8.7-16.2% for Rodentia, and 22.1% for Eulipotyphla. This causes deterioration in the food supply of many birds of prey and Mustelidae that feed on small mammals.

We have established that hydroelectric construction in the north of the Amur Region significantly reduces the species abundance and productivity of small mammal communities, which entails further losses in biodiversity. Due to both natural and anthropogenic factors, the coasts of large manmade water reservoirs turn into zones of reduced abundance of Rodentia and Eulipotyphla.

Acknowledgements. We are grateful to the management of the Zeya Nature Reserve for their help with organization and research.

Funding. This work was carried out for the Water Problems Institute of the Russian Academy of Sciences, theme No. FMWZ-2025-0002 “Researching the Formation Processes of the Surface and Ground Waters Quality, Natural and Anthropogenic Mechanisms of Ecological Changes in the Water Bodies, Development of Methods and Technologies for Managing Water Resources and Water Quality”, theme No. 1-22-37-1 of the Zeya Nature Reserve “Dynamics of Phenomena and Processes in the Ecosystems of the Zeya Nature Reserve and the Tokinsko-Stanovoy National Park”, state task No. 121051100137-4 of the Lomonosov Moscow State University (MSU) “Spatio-temporal Organization of Ecosystems under Environmental Change”; additionally, it was supported by the Development Program of the Interdisciplinary Scientific and Educational School of MSU “Future of the Planet and Global Environmental Change” and the Development Program of MSU (P. 1220).

Keywords: Rodentia, Eulipotyphla, fauna composition, population dynamic, influence zone of water reservoir, solar activity, precipitation, air temperature.

DOI: 10.24412/2542-2006-2025-2-104-129

EDN: YUUIHG