The vegetation of the Prisursky Nature Reserve has been insufficiently studied. The reserve’s location at the border of nemoral and taiga community types, along with significant topographical heterogeneity, creates various combinations of these communities. The aim of this study is to identify the relationship between the patterns of forest vegetation distribution and the landscape structure. The research was conducted in the Alatyrsky section of the Prisursky State Nature Reserve (Chuvashia). A geobotanical profile measuring 5.5 km was established in the basin of the River Lyulya, extending from the watershed to the floodplain. Within this profile, the additional 9 shorter profiles were built. A total of 314 geobotanical descriptions were used for analysis, conducted according to the Braun-Blanquet methodology on plots of 100, 25 and 2.5 m². To characterise the phytocenoses, the ratio of the main ecological-cenotic groups of species was analysed. The ecological space of the ecotopes was assessed using the scoring ecological scales developed by D.N. Tsiganov. Plant community types for phytocenosis characterisation were identified according to the principles of dominant classification. Forest catenae of two levels were described: the first-order catena (in the basin of the River Lyulya) and second-order catenae (its tributaries). Six types of ecotopes were identified in the first-order catena, with background and additional communities described for each. A comparative analysis of the species composition and the ratio of ecological-cenotic groups of the plant cover in the two levels of catenae was conducted. The internal heterogeneity of plant communities, related to topographical irregularities, is an inherent characteristic that should be considered when describing the plant cover of areas with complex landscape structures. Moving from the upper to the lower parts of the first-order catena, there is an increasing participation of boreal species with a decreasing role of nemoral species; in the floodplain ecotope, the proportion of nemoral species rises again. The distribution of plant cover in catenae of different scales occurs in a similar manner.

Marmots weren’t part of the ecosystems of Bryansk regions for a long time, because they disappeared under the pressure of the plow and uncontrolled hunting. In this area, the first colony of marmot was noticed in 2013 on the gentle slopes of the southern exposure. The aim of the work is to estimate the role of Marmota bobak activity for intraforest steppe meadows in the east of the Bryansk region. Route survey showed that plants communities transformed under their activity. Based on geobotanical relevés and statistical analysis, two groups of vegetation were identified in the study area: short-grass and tall-grass meadows. Tall-grass meadows are characterized by low biodiversity indices, because highly competitive grasses dominate the community (Bromus inermis, Calamagrostis epigeios, Elytrigia repens etc.). Small-grass meadows are associated with marmot settlements and are sustained by animal activity. Due to the grazing of dominant grasses, less competitive species can occupy more advantageous positions in the grass stand. The activity of marmots allows plant species of different ecological-coenotic groups to coexist in the meadows. To maintain structural and species diversity of the vegetation cover of intraforest meadows, the following features of marmots’ behaviour are important: formation of burrows with fresh throwings, which are characterized by an exposed substrate necessary for seed and vegetative propagation of plants; creation and maintenance of pasture or forage areas near the burrows. The above determines the development of vegetation patches (micro-groupings) in meadows and their spatial redistribution in communities.

This paper explores the features of bat distribution during hibernating in artificial caves of the Samara Bend (in the Samara Region). Data on microclimatic preferences of 7 species of hibernating bats and their tolerance limits in relation to air temperature and humidity in shelters were obtained, mathematical models of the dependence of bat distribution on the above factors were compiled. The study found that the species Plecotus auritus (Linnaeus, 1758), Eptesicus (Cnephaeus) nilssonii (Keyserling & Blasius, 1839), Myotis daubentonii (Kuhl, 1817) and M. mystacinus (Kuhl, 1817) have a relatively wide tolerance to the temperature of the shelter, relative stenothermy was found for M. dasycneme (Boie, 1825) and slightly less for M. nattereri (Kuhl, 1817). The temperature optimum for most bat species is +2…+4 °C. Species that tend to form clusters or occupy internal microshelters are able to endure hibernation in cooler parts of the caves. All the studied bat species are characterized by high tolerance to air humidity values in shelters.

The article is written in memory of Doctor of Biological Sciences, Professor Olga Vsevolodovna Smirnova (10.09.1939–12.30.2024), who was the editor-in-chief of the journal «Russian Journal of Ecosystem Ecology». The article describes her path in science and teaching activities. At the beginning of her research activity (1960s), she studied the population biology of forest herbs. Together with A.A. Uranov and a team of his students and collaborators, she contributed to the development of theoretical ideas about the structure and dynamics of plant populations. In the 1970–1980s, she expanded the scope of plant investigation and obtained a large amount of systematized data on the ecological strategies of several dozen herb species growing in broad-leaved forests. She published her monograph in 1987, describing methods and results of studying plant population strategies, becoming a pioneer on this subject in the Russian-language literature. At the same period, under the guidance or with the active participation of O.V. Smirnova, annual expeditions were conducted to study the population organization of various synusia in the communities of broad-leaved forests and mixed coniferous-broad-leaved forests. The scientific interests of the team gradually shifted to the population life of tree species, which are key species in forest ecosystems and impact the spatial structure of forest vegetation and soils, then, in turn, to the relationships of tree species populations with heterotroph populations of different taxonomic groups and trophic levels. During the expeditions, the research was not only descriptive, but sometimes also experimental: the structure of tree species populations was regulated in order to increase the structural and taxonomic diversity of forests. Comprehensive studies created a basis for reinforcing and developing theoretical concepts of world population biology and ecology, describing the structural and functional organization and self-regulation of ecosystems. Those were ideas about the mosaic-cyclic dynamics of ecosystems, key species of biota and the role of their population life, complementarity in interspecific relationships and its impact on biological diversity, as well as large-scale centuries-old anthropogenic transformation of ecosystems, which suppresses all the processes listed. Developing these concepts, O.V. Smirnova attached great importance to the mathematical modelling of populations, ecosystems and the processes they are involved in. She often initiated collaboration between population biologists and other field ecologists and mathematicians. In the 1990s and subsequently, the geography of plant-population and complex biogeocenotic studies covered all climatic zones where forests can be found, throughout the European part of Russia and various regions of the Asian part. Among the publications released based on the results of the conducted studies, the most famous was the 2-volume collective monograph «Eastern European Forests: History in the Holocene and the Present» (2004). When writing it, O.V. Smirnova was the editor-in-chief and inspired work of 49 authors from 19 scientific organizations. In the 2000s, as a sufficient theoretical result of her long-term work, O.V. Smirnova substantiated diagnostic criteria for assessing the successional status of forest ecosystems. She continued population and biogeocenotic studies until the last years of her life. She also always sought to disseminate among other researchers the concepts and methods that she used, for this she was actively involved in pedagogical work. In particular, in the 1990s and 2000s, O.V. Smirnova headed the master’s degree educational programme «Biogeocenology and Forest Ecology» at Pushchino State University, delivered the lecture courses «Biogeocenology» and «Historical Ecology» there and, by invitation, at other universities in Russia. Besides, she supervised numerous qualifying works of master’s degree students and post-graduate students, several applicants for the academic degree of Doctor in Biological Sciences. In addition to conducting scientific field research, O.V. Smirnova participated in expeditions with nature conservation aimsin the 1990s-2010s, using her knowledge and experience to justify the establishment of specially protected natural areas. Another practical application of the scientific concepts she developed was the repeatedly published practical recommendations for forest users. In the last years of her life, O.V. Smirnova was actively involved in popularizing the scientific views that she had been developing for a long time; for this purpose, she gave a course of lectures called “Ecology for Everyone”. O.V. Smirnova’s scientific heritage includes more than 300 publications, e.g. 28 monographs and 243 articles in peer-reviewed journals. One can read her works on her personal page in the Istina information system (https://istina.msu.ru/workers/7762639/).

The intensive production of food protein is an integral attribute of modern civilization. Poultry meat production is developing most dynamically all over the world and in Russia, in particular, because this industry is characterized by a short reproduction cycle and quick payback of invested funds. However, the growing rates and volumes of production also entail a progressive increase in waste masses. Litter and poultry litter are transported to landfills or directly to the fields, where over time they undergo natural degradation, accompanied by the emission of gases into the atmosphere and biogens into the soil and groundwater. The ingress of biogens and indigenous microflora of manure into the soil leads to changes in the composition of biocenosis components and the characteristics of their biotopes. The rate and efficiency of degradation depend on the enzymatic potential of the microflora present and the integral effect of endogenous and exogenous factors. Purpose of research: study of dynamics of species composition and environment-forming role of microflora of organic wastes of poultry farming in the processes of their natural destruction and consideration of factors determining the change of formations. In the process of work the following tasks were solved: study of indigenous microflora of poultry litter, study of composition of autochthonous, allochthonous and zymogenic microflora, study of microflora role in formation of substrate transformation vector (reaction and medium temperature), evaluation of microbial formation change regularities. The role of indigenous microflora of manure in the processes of ammonification as a starting stage of degradation of nitrogen-containing waste mass was established. From the process of ammonification starts the step-by-step degradation of manure-litter mixture. The shift of the pH range to the alkaline region caused by the activity of ammonifiers is a factor preventing the proliferation of fungal microflora and degradation of hard-to-degrade polymers. Exposure to high temperatures in the thermal phase of substrate composting is a selection factor sharply modifying the species composition and determining its deep reorganization. The determining role of autochthonous soil microflora at the final stages of organic waste degradation has been established. Species diversity of microorganisms in the masses of organic wastes naturally changes at different stages of degradation. The rates of microbial formations change decrease as the material decomposes, and the dynamic equilibrium of microflora composition is associated with the achievement of a stable balance of biogenic elements, mainly nitrogen and carbon.

Management of populations of rare predators is impossible without knowledge of the number and density of their main prey species. In the Southwest Primorskiy Province, the world’s only wild population of the Far Eastern leopard has been preserved, and the area is also part of the range of the Amur tiger. The main hunting objects of these rare predators are ungulates: sika deer, roe deer, wild boar. In 2019, a new ungulate species for Primorskiy Krai and Russia – the water deer – was discovered here. The aim of the work is to study the number and density of wild ungulates in the range of the Far Eastern leopard, to assess the dynamics of changes that have occurred in the populations over 3 years. Materials from two full-scale aerial surveys conducted in 2019 and 2023 were used to estimate the number and density of wild ungulates in the Southwest of Primorskiy Province. The survey routes covered the entire Russian part of the range of the Far Eastern leopard with an area of 571,000 ha, including hunting grounds and protected areas of national and provincial levels. Both surveys were conducted using the same methodology and under as identical conditions as possible. In 2019, the total length of the routes was 1104.8 km and 1298 sika deer, 264 roe deer, 301 wild boar and 11 water deer were encountered. In 2023, 1666 sika deer, 151 roe deer, 71 wild boar and 19 water deer were registered along 999.6 km. Since 2019, sika deer numbers have increased by 25 % to 28.9 thousand individuals at a density of 50.5 ind/1000 ha. Favorable conditions for population growth are created by highly productive oak-broadleaf forests, lack of stable snow cover in winter, as well as additional winter foraging and improvement of anti-poaching work on protected areas. At the same time, the roe deer number and density declined twofold, and by 2023 here was 2.8 thousand individuals at a density of 4.8 ind/1000 ha. The main reasons for the population decline are competitive relationships with sika deer, as well as hunting and poaching pressure outside the specially protected natural areas. As a result of the outbreak of African swine fever, the number of wild boar in the Southwest Primorskiy Province has decreased more than 4 times in three years to 1.3 thousand individuals at a density of 2.3 ind/1000 ha. Water deer population in the south part of the study area was doubled in three years and totaled about 300 individuals at a density of 2.8 ind/1000 ha. Despite the depression of wild boar and roe deer populations, due to the growth of sika deer numbers, the total population of wild ungulates in 2023 remained at the level of 33 thousand animals, which provides prey for the growing populations of the Far Eastern leopard and Amur tiger. The number of sika deer in the study area reached a historical maximum. The population growth indicates that the south-west of Primorskiy Province has the most favorable conditions for this species. With the increasing population of sika deer, roe deer will continue to be displaced from forested areas into open habitats. It is likely that the core roe deer population will remain in rare forests and meadow habitats in the south of Khasanskiy District. It is not known whether the ban on wild boar hunting announced in Primorskiy Province will affect the recovery of the population of this species. The prognosis for the outcome of the disease and the recovery of animal numbers is currently unclear. The rapid growth of the water deer population in the Russian part of its range is not surprising. The combination of favourable environmental factors is complemented by early puberty and high fertility of animals.

The food supply is a key factor determining the reproductive performance of populations of the large feathered predators. The distribution of the Imperial Eagle Aquila heliaca is primarily limited by the distribution and abundance of the main prey species, namely large colonial steppe rodents (ground squirrels and marmots). Despite the wide adaptive capabilities of the Imperial Eagle for food supplies, the role of secondary prey species in feeding of the young remains an urgent research topic. Modern methods of autonomous video surveillance used in this work enabled exploring the diet of a pair of the Imperial Eagles in the Sengileevsky Mountains National Park. The studies were conducted in 2023-2024 in the period from March to September. An autonomous video surveillance system was used for the observations. During the entire observation period, 444 prey items brought by the adults to the nest were recorded, of which 428 items were identified to the species, genus, family, order or class. 34 items of wild fauna belonging to 4 classes of vertebrates were identified in the diet of a pair of the Imperial Eagles. The maximum food intake is observed in June and July. The main prey items are Russet ground squirrels (20 %), common field voles (19 %) and steppe marmots (12 %). Large steppe rodents predominate in the diet at the initial stages of feeding of hatchings (June). The proportion of large birds in the diet increases significantly during the feeding period of nestlings and fledglings (July-August). When raising two offerings, compared with one, there is a multiple (by an order of magnitude) increase in the number of large birds in the diet of the Imperial Eagles in the late stages of feeding nestlings and fledglings. Despite the adaptability of the Imperial Eagles in choosing prey items, large rodents of open spaces remain one of the key food supplies. Large steppe rodents, mainly colonial ones, ensure the continuity of feeding the young during the most critical period of their development. The diet of the Imperial Eagles can include almost the entire range of vertebrates found in the breeding territory of a pair.

The structural and functional organization and dynamics of the development of generative shoots in boreal willow species have not been sufficiently studied yet, which determined the aim of the study. The structure of spring generative shoots of regular renewal and summer secondary flowering generative shoots was examined in 16 species of boreal willows. Attention was paid to the time of the appearance of generative shoots, the length, the degree of vegetation and the duration of the vegetative zone. In S. myrsinifolia, the location of male and female flowers in bisexual inflorescences and the location of generative shoots (male, female, and bisexual) in the plan shoot system were revealed. The study found that the examined willow species can develop, in addition to generative shoots of regular renewal, secondary flowering generative shoots. Generative shoots of regular renewal are divided into single-stage falling (S. caprea, S. vinogradovii, S. gmelinii, S. acutifolia, S. viminalis, S. aurita, S. lapponum), two-stage falling (S. alba, S. euxina, S. triandra, S. cinerea, S. myrsinifolia, S. starkeana, S. rosmarinifolia, S. myrtilloides) and conditionally non-matching (S. pentandra). Among the secondary flowering generative shoots, 5 variants were identified, differing in the length and variety of the vegetative zone. Secondary flowering generative shoots can be divided into summer and late summer shoots according to the time of appearance. In the same species, generative shoots of regular renewal and secondary flowering generative shoots may differ in the structure of the vegetative zone. In S. myrsinifolia, male, female, and bisexual inflorescences can form on the same plant, while generative shoots with male inflorescences develop from both wintering buds and dormant buds. Polymorphism of generative willow shoots is determined by the degree of vegetation and duration of the vegetative zone, the time of formation of generative shoots, the formation of not only unisexual, but also bisexual inflorescences.

The article investigates the distribution, species, and projective cover levels of vegetation that emerged in the sand dunes formed in place of the Aral Sea due to its desiccation. The changes in vegetation over the years, from 1981 to 2024, have been studied. According to the results, the projective cover level of vegetation on the dried Aral Sea bed has undergone significant changes. Specifically, from 1981 to 2024, the projective cover level increased by 31 %, reaching 55 %. Currently, dominant plant species such as Haloxylon ammodendron (C.A. Mey.) Bunge ex Fenzl, Halostachys caspica (M. Bieb.) C.A. Mey., Halocnemum strobilaceum (Pall.) M.Bieb., Haloxylon persicum Bunge, and Caroxylon nitrarium (Pall.) Akhani & Roalson are widespread. In the study area, factors such as increased soil salinity, changes in groundwater levels, low precipitation, and rising temperatures have had the most significant impact on the distribution and changes in vegetation. In the early years of the Aral Sea desiccation, approximately 10 plant species grew, with a projective cover level of 24 %. Over the course of 10 years, the number of species increased by 1–2 species. After 20 years, the number of species decreased to 7, but after another 20 years, the number of species increased again, reaching 11 species. The projective cover level increased from 24 % in 1981 to 55 % by 2024, showing a 31 % increase.