Sub-Mediterranean landscapes with high biodiversity, rare and endemic species of flora and fauna are unique for Russia, being formed on the Black Sea coast with intensive and prolonged anthropogenic effect, in the most northeastern area of Mediterranean ecosystems of Europe. The main object of this study was the Utrish Nature Reserve, which was organized in 2010 to protect these landscapes in the North-Western Caucasus. It became a model area for large-scale complex study and monitoring of sub-Mediterranean forest landscapes under current climatic changes, including their restoration after previous anthropogenic effect. Large-scale landscape and botanical maps, compiled on the field complex descriptions on sample sites, repeated observations on the model plots with special attention to vegetation, and the analysis of remote sensing data were used to identify factors of formation, structure and dynamics of vegetation and landscapes. The relationship of vegetation to abiotic conditions was determined by statistical methods. The main factors and basic regularities of the spatial organization of vegetation and landscapes, and phytocoenotic diversity were revealed on the basis of landscape and botanical maps (1:25,000 and 1:50,000) and transects. The dominance of slope geosystems and their maximum diversity, altitudinal zonality with formation of sub-Mediterranean landscapes at 0–250 m a.s.l., the asymmetry of geosystems are typical for the landscape structure, which determines the heterogeneity of vegetation. Coastal landscapes are distinguished by the more complex spatial structure and high biodiversity with rare and relict species, including a high participation of Mediterranean species. The sea–land contact zone with the predominance of abrasion types of shores is characterized by dynamism, which leads to the destruction of part of the coastal landscapes. Vegetation restoration after recreational use and fires, including a major fire in 2020, was determined based on the study of monitoring plots. Rapid formation of herb and shrub layers began after the fire, the structure of which had both similar features in different communities and differed in its specifics. The results of the research formed the basis for expanding the boundaries of the reserve in 2021 at the expense of coastal geosystems that were not previously included and the organization of monitoring.

The uniqueness of the Abrau peninsula is determined by a high level of floristic and phytocoenotic diversity and the relict nature of the vegetation cover of the shiblyak—broad-leaved type of altitudinal zonality. For this mountain territory, a complex spatial organization is reviled. In this research, a cartographic method for the evaluation of the vegetation cover of a mountain territory has been approved by identifying its spatial structure. The complex analysis of field data (geobotanical descriptions) and remote sensing data (multispectral satellite images, digital elevation model) made it possible to obtain a digital cartographic model of vegetation for the key area using maximum likelihood classification with etalons and discriminant analysis. The compiled large-scale (s. 1:50,000) inventory map of the vegetation reflects the actual vegetation cover, represented by a diversity of hemixerophytic sub-Mediterranean and mesophytic nemoral communities. The change in the basic communities in the altitudinal spectrum determines the identification of two belts. The lower seaside belt of hemixerophytic forests, sparse forests, and shrub communities is expressed at heights of 0–150 (200) m a.s.l. It is characterized by the development of pistachio-juniper (Juniperus excelsa, Pistacia mutica) forests and sparse forests, oak (Quercus pubescens) forests, as well as serial vegetation with shrub and herb-dwarf shrub petrophyte-herb communities. The belt of mesophytic broad-leaved forests is located at heights of 150 (200)–450 m a.s.l. Pine-oak (Quercus petraea, Pinus kochiana) and broad-leaved (Carpinus betulus, Tilia begoniifolia, Acer campestre) forests dominate in it. The important patterns in the spatial structure of the belt are expressed within the altitudinal belts. The structure of vegetation communities is formed under the conditions of several groups of relief forms: watershed surfaces, slopes, seismic forms, erosion forms, and marine forms. The most valuable results of the investigation are connected with reviling the gradients of phytocoenotic diversity. Along with altitudinal gradient, the position on different levels of catena has significant role in its determination. The identified spatial patterns are important for understanding the formation of Northwestern Caucasus ecosystems as a part of Mediterranean region.

This article considers the ecological and geographical features of officinal plant distribution within the highlands of Northeastern Transbaikalia. The concept of ecosystem diversity is used as a methodological basis of the study. According to it, the orobiome presents a key regional unit for the inventory and assessment of mountain biodiversity. Comparative geographic and cartographic methods of analysis of original field data, papers, and maps are applied. We have identified 40 species of pharmacopoeial plants for the Northeastern Transbaikalia orobiome. The taxonomic, biomorphological, ecological, geographic, and altitudinal characteristics have been considered, and the analysis of composition of active substances and use in the treatment of diseases according to the ICD-10 international classification of diseases has been carried out. It has been revealed that the highest number of species are applied when treating diseases of the digestive system, diseases of the circulatory system, and diseases of the respiratory system. Five geographical groups of pharmacopoeial species have been identified, among which species with the Holarctic distributional type prevail. Boreal species predominate among nine ecological–coenotic groups. The coenotic value of pharmacopeial species in vegetation communities of the orobiome is considered. Some species of officinal plants are coenose formers, predominant in the background communities for the belts; they include Sctoch pine, Siberian fir, lingonberry, marsh rosemary, downy birch, and bearberry. The regional and altitudinal features of pharmacopeial species distribution have been revealed. The highest number of species grow on the North Baikal Highlands, while the smallest number are on the Patom Highlands. There are more than 20 species in the mountain–taiga belt and about 5–10 species in the high-mountain belt. A map of communities with the participation of typical species of pharmacopeial plants of resource importance has been compiled. It has been revealed that the greatest diversity of these resources is concentrated on the North Baikal Highlands due to climatic conditions and the geographical location at the junction of biogeographical boundaries. The map can be used to assess the ecosystem potential of the vegetation cover of a poorly explored region. The expediency of further study of the pharmacological properties of local flora species used in traditional medicine, as well as strengthening of measures for the protection of medical plant species, is noted.

Освещены проблемы инвентаризации, оценки и мониторинга биоразнообразия на основе картографирования как развивающегося самостоятельного направления исследований, позволяющего проводить пространственный анализ биоты с использованием широкого спектра тематических карт. Рассмотрены примеры выявления разнообразия биоты, которое проводится с помощью картографического метода на четырех основных уровнях: видовое богатство конкретных (локальных) флор, фитоценотическое (видовое богатство и разнообразие сообществ растительных формаций), определенных природных комплексов (ландшафтное биоразнообразие) и экосистемное разнообразие. Дан краткий экскурс в историю формирования теоретико-методических принципов картографирования биоразнообразия, в результате которого к настоящему времени подготовлены сотни карт, отражающих разнообразие организмов на основе разных подходов и методических разработок. К ним относятся карты флористического и фаунистического разнообразия мира (схемы изолиний, связывающих точки с одинаковыми количественными показателями оценки уровней флористического и фаунистического видового богатства в пересчете на определенную площадь); карты на сеточной (растровой) основе (использование ячеек определенной площади с отметками присутствия-отсутствия вида или комплекса видов в каждой из ячеек); карты, составленные на основе моделирования числа таксонов в зависимости от условий среды (метод моделирования по экологическим параметрам); карты фитоценотического разнообразия. Показаны примеры успешного применения данных дистанционного зондирования Земли, прежде всего космических снимков, для создания и использования разномасштабных карт, что открывает новые возможности в исследовании биоразнообразия. Представлен эколого-географический подход к выявлению и оценке биоразнообразия, перспективы которого связаны с его изучением в естественных границах подразделений биотического покрова разного уровня на основе экологических единиц подразделений биосферы - региональных биомов. Особое значение такой подход приобретает при исследовании фундаментальных проблем географии биоразнообразия горных территорий. This outlines the issues related to inventory, evaluation and monitoring of biodiversity, based on mapping as a developing independent research direction that allows for the spatial analysis of biota based on using a wide range of thematic maps. Examples of identifying biota diversity are considered using the cartographic method at four main levels: species richness of concrete (local) floras, phytocoenotic diversity (species richness and diversity of communities of vegetation formations), natural complexes (landscape biodiversity), and ecosystem diversity. A short historical overview of the gradual formation of theoretical and methodological principles of biodiversity mapping is given. As a result of these principles, hundreds of maps have been prepared to date, reflecting the diversity of organisms based on different approaches and methodological principles. There are maps of the floristic and faunistic diversity of the world (isoline diagrams connecting points with the same quantitative indicators for assessing the levels of floristic and faunistic species richness of a certain area); maps on a grid (raster) basis (the use of cells of a certain area with marks of presence-absence of a species or a complex of species in each of the cells); maps compiled on the basis of modeling the number of taxa depending on environmental conditions (modeling method by ecological parameters), and maps of phytocenotic diversity. Examples of the successful application of Earth remote sensing data and, above all, satellite images are shown for the creation and use of multi-scale maps that have new prospects in biodiversity studies. In the final part of the paper, an ecological-geographical approach to the identification and assessment of biodiversity has been considered. Its prospects are related to the study of biodiversity within the natural boundaries of biotic cover units of different levels on the basis of ecological units of biosphere subdivisions - regional biomes. This approach is of particular importance in the study of fundamental problems of the biodiversity geography of mountain areas.

Пожар 2020 г. на территории заповедника Утриш, расположенного на полуострове Абрау (Северо-Западный Кавказ), привел к уничтожению уникальных субсредиземноморских гемиксерофитных низкогорных ландшафтов Северо-Восточного Причерноморья на площади более 100 га. Целью работы является изучение процессов вторичной сукцессии сообществ и выявление их закономерностей. Данные комплексных исследований свидетельствует о высокой интенсивности процессов восстановления компонентов нарушенных экосистем.

Search for correlations between different soil properties and assessment of their variability is important for understanding soil functioning, allows more optimal planning of field and laboratory research and creates the basis for fertilizing management and precision agriculture. This work is based on the data on the content of organic carbon, pH, bulk density, texture (fractions 1-0,25 mm; 0,25-0,05 mm; 0,05-0,01 mm; 0,01-0,005 mm; 0,005-0,001 mm and <0,001 mm and <0,01 mm), exchange calcium and magnesium carbonates for twelve sites of plowed Chernozems studied in the southern part of the Central Russian Upland (Belgorod oblast). Soil samples were taken layer by layer every 20 cm to 3 m depth. Weak correlation was revealed among studied soil characteristics of the plowed Chernozems. The least correlation with other soil characteristics is characteristic of bulk density, organic carbon content, content of fraction 0,25-0,05 mm and 0,01-0,005 mm. Correlation between the content of bicarbonates and pH values is observed only for accumulative - carbonate horizon and transition horizons. The largest number of correlations between different soil characteristics is for the non-plowed part of humus horizon and the top of transition horizon. The least amount of correlations between soil characteristics was found at depths from 80 to 100 cm. Comparison of the coefficients of variations calculated for different soil layers of a single profile (i. e. intraprofile variability) and for the same soil layers but from different profiles (i. e. lateral variability) showed that the intraprofile variability exceeds the lateral one for the organic carbon, exchangeable potassium and calcium content.

A bioclimatic justification is made for the diversity and structure of vegetation cover of the Russian mountains. On the basis of identifying the climatopes of the altitudinal-belt subdivisions underlying the spectra of mountain systems and analyzing the related development of the vegetation cover of orobiomes with climatic conditions, the possibilities for its formation within the framework of altitudinal spectra have been determined. A global CHELSA model has been used to obtain reference bioclimatic parameters. The average annual temperature, the temperature of July and January, annual precipitation and precipitation of July, radiation balance, and continentality index and ombrothermic index of July have been used as key bioclimatic parameters. The diversity of altitudinal-belt subdivisions (belts and subbelts) has been determined on the basis of the altitudinal zonation of vegetation and the hierarchical structure of the botanical diversity of mountains and the types of zonation formed by them. On the basis of calculating the mean values and standard deviations of heat and moisture availability within the entire climatic area occupied by background communities in terms of orobiomes, their climatopes have been determined and a clustering has been carried out. As a result of comparing the climatopes at higher hierarchical levels, thermoclimates (extremely cold, very cold, cold, moderately cold, and moderately warm) and ombroclimates (moderately continental humid, moderately continental very humid, continental humid, and extracontinental semi-humid) have been determined. Mapping of climatope diversity made it possible to determine the relationship between the typological structure of altitudinal-belt spectra of vegetation with modern climate on a unified ecosystem basis.

An analysis of the spatial organization of vegetation cover has been carried out for the Altai-Sayan orobiome in connection with climatic conditions in the Southern Siberian mountains based on original relevés of plant communities at the 4 altitudinal spectra. Basic bioclimatic parameters on the altitudinal spectra of vegetation have been determined according to latitudinal and longitudinal differentiation of climate. Correlation and discriminate analyses allowed to identify the regional features of altitudinal gradients in species diversity of the spectra as well as the role of parameters in the structure of typological diversity of vegetation for belts of high-mountain tundra, alpine and subalpine meadows and sparse forests, dark coniferous mountain taiga forests, chern-taiga forests, small leave – light coniferous subtaiga forests, forest-steppe. A compiled bioclimatic scheme characterizes the spatial organization of orobiome’s vegetation by basic bioclimatic parameters on the regional level (continentality index, average temperature of January). This scheme shows regional features of the diversity of vegetation in Southern Siberia, in adjacent plain and mountain regions according to climatic conditions. Identified patterns determine unity of the Altai-Sayan orobiome as well as regional differentiation that reflected on the development of types of vegetation zonality. They can be used to analysis of vegetation forming in different mountain systems.

— The most important spatial patterns of plant cover of the Northern Transbaikalia, its regional features being represented by the structure of altitudinal zonality of the Northeastern Transbaikal orobiome, have been determined in relationship with the climatic factor. The regional climate assessment of the altitudinal belt structure of the plant cover of the orobiome has been performed for typological subdivisions of the highest hierarchic level (phratries of the classes of plant formations) using the BioClim global climate model. Principal component analysis, discriminant and cluster analysis were used to demonstrate that the summer ombrothermic index, continentality and climate moisture indices and the mean annual rainfall of many years are the most significant bioclimatic parameters determining the spatial structure of plant cover in the mountain taiga, subgoletz, mountain tundra and goletz belts. The background communities of orobiome belts develop under the conditions of continental climate (continentality index from 36 to 50). Heat supply parameters, first of all, in the vegetation period, are crucial for the spatial differentiation of altitudinal subelts, characterizing the change of light forest and dwarf pine communities in the subgoletz belt, larch, larch–pine and dark-coniferous forests in the mountain taiga belt. Moisture supply is related to the regional differences in the typological diversity of the belts, which are manifested in the development of more moisture-demanding fir–spruce forests in the low parts of the Patom Highland (rainfall amount more than 450 mm per year) and pine forests in the intermountain basins of the Stanovoy Highlands, existing under the conditions with the maximum annual temperature amplitude and low rainfall levels (up to 400 mm per year).

Introduction. The article summarizes the experience of the teachers of the Department of Biogeography of Lomonosov Moscow State University, accumulated during remote teaching and organizing field practices for students under restrictive measures during the COVID-19 pandemic in 2020-21. The sudden introduction of remote learning required an urgent adaptation of academic programmes, the modification of existing teaching technologies to the new format, and a rapid restructuring of the educational process. Materials and Methods. The use of a new textbook with presentations and video materials, archival materials, educational and methodological and scientific publications, video recordings describing characteristics of individual plant and animal species, the structure and composition of particular phytocenoses, issues of their protection and anthropogenic transformation. Published materials on the biological and landscape diversity of Moscow City and the Moscow Region and on the specifics of anthropogenic transformation in this territory and ongoing conservation measures are used. Results. Determination of the methodological basis and development of principles for organizing and conducting classes and field practices in the context of anti-COVID-19 restrictions and analysis of the experience gained in order to determine the possibility of its application in similar circumstances. Discussion and Conclusions. In the context of distance learning, approaches to the demonstration of visual materials during classes were changed, the presentations that replaced the explanations of teachers in the exposition of the Museum of Geography of Moscow State University (the main training ground for practical work on the course "Ecology with the basics of biogeography") were created. Field practices were reduced, moved to new locations and reformatted in terms of approaches to the study of flora, geobotanical profiling and writing a report. The experience gained was positive and the work results received high marks in the surveys of students and teachers. The developed approaches can be used in case of new restrictions, as well as when working with people with disabilities.

Biodiversity geography is now rapidly successfully developed within general biogeography, encompassing many aspects of biota differentiation on various levels of the biotic cover organization. This study concerns the biodiversity geography from the standpoint of the basic classification of terrestrial ecosystems, utilizing an ecological–geographical approach to interpret their biodiversity; it substantiates regional orobiomes as basic units for assessing the species and ecosystem diversity of mountains. The purpose of this study is to identify the regional specifics of typological diversity of mountain forest ecosystems and biota in connection with the altitudinal-belt structure and altitudinal gradients and to determine their role in the organization of mountain space with respect to its ecotopic structure. To achieve the purpose, statistical methods for processing digital cartographic models of vegetation, relief, and climatic conditions are used. The altitudinal-belt structure of the plant cover was revealed by the example of the Northeast-Transbaikalian taiga orobiome. The spatial structure of the mountain taiga belt, reflecting its typological diversity, was revealed on the basis of a small-scale map of orobiome forests. The mountain taiga belt (with two subbelts) determines the regional specificity of the floristic and cenotic diversity of East Siberian mountain forests of the orobiome. Larch forests predominate in the forest cover of the belt, pine and dark coniferous forests take a limited part, and the species composition decreases along the altitudinal gradient. Along with the features common for the orobiome, there are also specific features of forest biodiversity in its geographical variants associated with different ratios of typological units at different altitudinal levels. The key parameters of heat and moisture supply of high-altitude belts are determined for the mountain taiga belt; they characterize the climatic conditions for the biodiversity formation in the mountains of the Northern Transbaikalia. The successful use of orobiomes in the analysis of biodiversity of the mountain areas determines the prospects for studying forests and for developing a system for their monitoring and protection on a single biome basis.

Based on the biome concept in biogeography and the ecological-geographical approach to the analysis of biodiversity, a regional assessment of the Southeast Altai-Tuva orobiome, which is unique for Russia, is given. The orobiome is considered as a reference unit for the inventory and analysis of the ecosystem and biotic diversity of mountain areas. The characteristics of bioclimatic indicators characterizing the originality of the desert-steppe orobiome of the Subarid class of zonality types and its altitudinal zones are given. The altitudinal structure of the vegetation cover is revealed, in accordance with which the spatial differentiation of flora, plant communities, and ecosystems as a whole is formed. A quantitative assessment of floristic (about 1400 species of vascular plants) and phytocoenotic diversity by zones (nival, desert-tundra, forest-steppe, and steppe) is given. The features of the spatial structure of the diversity of communities in the conditions of a mountainous territory are revealed.

This paper is devoted to evaluation of the spatial structure of subtaiga light coniferous forests on the southern border of the boreal region. Investigations were carried out on two key sites (on the northern macroslope of the Hangai range and its lowlands) during the Joint Russian-Mongolian Complex Biological Expedition in 2021. Geobotanical descriptions of larch and pine forest subtaiga communities were made in the course of field works. These descriptions were completed according to standard geobotanical methods. They are the basis of compiled thematic forest maps for two polygons. Forest maps were made on the basis of complete and short geobotanical descriptions, satellite images, and a digital elevation model. The analysis of relations of forests with altitude, slope steepness and exposure was made using the cartographic method. This analysis made it possible to determine the position of forests in the structure of altitudinal zonality of the region. Larch forests grow on the gentle slopes of the northern exposure of the Hangai range at altitudes of 1700-2300 m. They form complex spatial combinations with the steppes. Pine forests grow on steep slopes at the altitudes of about 1200-1700 m on the lowlands of the Hangai range. They are also grow on light exposures slopes.

Predictive ecosystem mapping is the basic tool for the conservation of biodiversity and its spatial structure analyses. This paper presents an ecosystem mapping approach that connected remote sensing data (SRTM, Landsat) and soil (at 92 points) and vegetation (at 64 points) description for the key site located at Tigirek nature reserve (West Altai). The linear discriminant analysis with stepwise selection of predictors (more than 60 morphometric parameters and spectral indices) is used to modeling of the vegetation and soil spatial structure. The topography classification is based on exposition and slope steepness. The ecosystem map is compiled through an overlay of soil, vegetation, and relief maps and contains 38 units. The altitude, slope, and reflection (Landsat 5, October 2011) are the main factors that determine the soil cover spatial structure; the user's accuracy of the model is 64 %. Greyzemic Chernozems (100 %), Gleyic Cambisols (92 %), and Rendzic Leptosols (89 %) have the best quality of discrimination. Altitude and 3 spectral parameters (wetness, brightness, EVI) determine the vegetation spatial structure; the user's accuracy of the model is 73 %. The dominance of mesophilic meadows and shrub communities, and also small-leaf and light coniferous forests reflects the regional features of Altai forest-steppe ecosystems. Shrub communities with Caragana arborescens in combination with Gleyic Chernozems and Gleyic Cambisols on different slopes are predominant ecosystems in the key area. The area of meadows with Dactylis glomerata and Bromus squarrosus, formed mainly on Chernic Phaeozems and Gleyic Chernozems, Cambisols, Rendzic Leptosols, and Novic Retisols on uplands and slopes of different exposure, are the second and third on the key site. The analysis of components of ecosystems characterizes the limited opportunities of indication of soils by vegetation due to only a few vegetation communities have strong confinement to soils (the area of such vegetation is about 10 % of the key site).

The paper presents the results of the vegetation cover interpretation using multitemporal thermal satellite images of two mountain-steppe areas: in the Southern Urals (Abzelilovsky district of the Republic of Bashkortostan) and in Kuznetsk Alatau (Ust-Abakansky and Shirinsky districts of the Republic of Khakassia). These areas have a large amount of field data on vegetation, which allows for reliable verification of satellite data. On the basis of field data and images of high spatial resolution in the optical range, vegetation maps were compiled, which became the basis for further interpretation of thermal images—images of the TIRS sensor, Landsat 8 satellite, were used. Methods of controlled and uncontrolled classification were applied to multitemporal images. In the course of the study, it was possible to establish that, based on the results of vegetation interpretation using thermal satellite images for a site in the South Urals, it is possible to determine forest areas with good reliability (up to 50–70 %), and confidently draw the border between forest and treeless areas. With satisfactory accuracy (up to 44 %), petrophytic steppes are determined. The site in the Southern Urals is characterized by a small size of the territory, a low diversity of plant communities, and rather a large dependence of the intensity of thermal radiation on the exposure of slopes. The site in Kuznetsk Alatau showed more representative interpretation results. Larch and birch-larch forests (up to 70 %), fir and birch-fir forests (up to 56 %), dwarf birch and moss-lichen tundras (up to 49 %), and steppe vegetation (up to 45 %) are most confidently recognized.

The uniqueness of the Abrau Peninsula (Fig. 1) is determined by a high level of floristic and phytocoenotic diversity and the relict nature of the vegetation cover. Сomplex spatial organization of the vegetation cover is reviled for this mountain territory (Sus­lova, Petrushina, 2007; Ogureeva et al., 2020). It is associated with heterogeneity of ecotopes. In this paper, a cartographic method has been tested to assess the vegetation cover of a mountainous territory through the identification of its spatial structure. Based on the coupled analysis of field data (geobotanical descriptions) and Earth remote sensing materials (multispectral satellite images, digital terrain model) using the classification of spectral features of communities by the maximum likelihood method using etalons and discriminant analysis, a cartographic model of a key area of the Vodopadnaya Shchel valley was obtained (Fig. 3). It reflects the diversity of basic vegetation formations and types of vegetation and the heterogeneous structures formed by their plant communities. The key factors of vegetation cover formation and its connection with the landscape structure of the territory were determined based on the spectral brightness variables of the images and relief features (Kozlov et al., 2008; Rocchini et al., 2013). The calculated relative diversity indices (Shannon and Simpson indices) made it possible to quantify the main factors determining the spatial structure of the vegetation cover of the Abrau Peninsula. The created large-scale (S. 1 : 50 000) inventory vegetation map of the Vodopadnaya Shchel reflects the actual vegetation cover, represented by a diversity of vegetation communities, belonging to hemixerophytic sub-Mediterranean and mesophytic nemoral formations (Fig. 6). The change of background communities along the high-altitude spectrum determines the allocation of two belts. The lower belt of hemixerophytic forests and woodlands is located at altitudes of 0–150 (200) m a. s. l. It is characterized by the development of pistachio-juniper (Juniperus excelsa, Pistacia mutica) forests and woodlands, oak (Quercus pubescens) forests, as well as serial vegetation with shrub and dwarf semi-shrub-herb communities. This belt is characterized by a high level of floristic and phytocoenotic diversity and a complex spatial structure associated with the contrast of ecotopes. The belt of mesophytic broad-leaved forests is located at altitudes of 150 (200)–450 m a. s. l. It is formed by pine-oak (Quercus petraea, Pinus kochiana) and polydominant broad-leaved (Carpinus betulus, Tilia begoniifolia, Acer campestre) forests. The spatial structure of the vegetation cover is formed under the influence of the altitudinal gradient and, within the belts – a variety of ecotopic factors under the conditions of seismic-gravity processes (Petrushina, Merekalova, 2017). There is a gradual transition from one belt to another, as a result of which the position of the boundaries of the altitudinal belts varies depending on the type of morphostructures, the steepness and exposure of the slopes. Spatial patterns in the distribution of phytocoenotic diversity within and between altitudinal belts are associated with a complex of conditions, the gradients of which are expressed between different landforms and in connection with changes in morphometric characteristics, as well as the dynamic status of communities. The closest connections were found with the indicators of absolute height, the exposure of slopes, as well as in accordance with the catenary structure of the territory. The closest connections were found with absolute altitude, slope exposure, as well as with different geochemical positions of catena. Cartographic analysis revealed the main gradients of the spatial structure of the vegetation cover of the Abrau Peninsula. They are associated with an integral altitudinal gradient, under the influence of which an increased variety of sub-Mediterranean formations of the lower belt is formed. The increase in moisture supply determines the tendency to increase the diversity from eluvial to accumulative positions of catena in both altitudinal belts (Table 4). The revealed spatial patterns are important in understanding the formation of orobiomes presented on the map “Biomes of Russia” (Biomy …, 2018) and the mountain ecosystems formed by them within the altitudinal belts of vegetation.

The distribution of the vascular plants species occurring in the composition of high mountain communities with the participation of stitchwort polster (Stellaria pulvinata Grub.) are analyzed. They form a separate altitudinal belt in the altitudinal-zonation range of vegetation and belong to the arid class of zonality types in the central Mongolian Altai (2700–3300 m a.s.l. Baltic System (BS)). The analysis identified cenotically active species in the cenofloras of cryophytic steppes and cryophytes–forb cushion plants, which include distinctive elements of cryo-xerophytic conditions, such as Oxytropis oligantha, O. chionophylla, Saussurea leucophylla, Chamaerhodos altaica, Arenaria meyeri, and Androsace septentrionalis; montane species confined to the high mountain areas of southern Siberia and central Asia (Festuca kryloviana and Poa altaica) and bunchgrasses, which are represented by widely distributed species typical of the steppe (Festuca lenensis and Koeleria cristata). Modeling of the spatial distribution revealed that the ecological–cenotic optimum for the majority of species in the region is found outside of the cryophytic steppes and cushion-plant growth area. According to the identified potential distribution ranges of species accompanying Stellaria pulvinata, a close relationship has been established between the vegetation of the central Mongolian Altai high mountains and the mountains of southern Siberia.

The investigation of the Eastern Mongolia steppes of three-feather formation (Stipa grandis, S. krylovii, S. sibirica) was carried out in 2008–2019 on 11 test plots of 100 m 2 each, located along a transect within the intermountain plain south of the Kerulen River valley. The structural organization of steppe communities is considered as a criterion for the sustainability of ecosystems under changing climatic conditions. It is determined by the ratio of life forms, i. e. biomorphological types of plants, identified by the adaptations to vegetative growth (vegetative mobile; growing vegetative weakly mobile; vegetative immobile and nongrowing), and the biomorphological groups (turf, root, rhizome, root proliferous, annual-biennial), as well as the composition of dominants and the species richness of communities. Deviance of bioclimatic indicators from the long-term average values (1962–1990) was determined for the period of observation. Combinations of the life forms of plants and changes in the structural organization of communities were revealed. The structure of communities was statistically verified between different years (ANOVA, Kruskal-Wallis test). According to the change in moisture conditions (May-July precipitation, i.e. months with the maximum accumulation of phytomass) and the deviation from the long-term average values (100%), the observation years were classified into three groups: arid ( 190 mm, >130%). Years with increased moisture are characterized by maximum values of summer and May-summer ombrothermic index; while in the years with poor moisture and relatively low thermic conditions the values are minimal. In the years with medium moisture conditions, the species richness was particularly high and the species of all biomorphological types were present. This is the most favorable situation for the development of steppe communities. The species diversity of growing vegetative weakly mobile species decreases in the years with dry conditions, while that of vegetative immobile and non-growing species decreases in the years with wet conditions. The years with different moisture conditions also significantly differ in the projective cover of autochthonous assectors (Cleistogenes squarrosa, Agropyron cristatum, Potentilla acaulis) and digressive edifiers (Artemisia frigida). However, the floristic-coenotic core of communities, which ensures their stability, is preserved throughout the entire period of research; it includes 25 perennial species with high constancy in communities. The structural organization of three-feather formation steppes is reflected in species diversity and phytocoenotic role of particular biomorphological groups of species, and determines the natural potential of steppe ecosystems.

The quantitative assessment of ecosystem diversity is a basic tool for the evaluation of its resilience to anthropogenic loads and climatic changes. Our work is devoted to the large-scale predictive ecosystem mapping of hard-to-reach West Altai Mountain areas as well as vegetation, soil, and ecosystem quantitative diversity assessment (basing on Shannon and Simpson indices). The key site (7x4.5 km area) located in the Tigirek State Natural Reserve in the humid climate of the windward part of Altai. The predominance of shrub meadow communities and forb meadows on Gleyic Chernozems and Gleyic Chernic Phaeozems, Gleyic Cambisols, as well as the development of larch forests on the slopes of shady exposures on Greyzemic Chernozems are the regional specificities of the forest-steppe Altai ecosystem. Steppe communities (located on the Haplic Chernozems, Cambisols, and Leptosols), occupy less than 2% of the key site. The studied mountain forest-steppe ecosystem of West Altai is characterized by an extremely high level of spatial diversity: the Shannon index is 3.28, the Simpson is 0.95; an increase in soil diversity leads to a linear increase in vegetation diversity.

The spatial distribution of Caragana jubata (Pall.) Poir. is analyzed on the basis of herbarium materials, literary data and online documents. The analysis of spatial distribution of Caragana jubata made it possible to reveal the heterogenic distribution of occurrence sites of the species, resulting from the history of species origin and resettlement, as well as its coenotic association. Caragana jubata has a disjunctive area. Moving northward from the center of origin in the Himalayas and the Tibetan Plateau through the mountain systems, the species found favorable habitats in the mountains of the Eastern Sayan and the Stanovoye Highlands, where it is a relict of the Tertiary period. Basing on the map of the spatial distribution, the geographical aspects of Caragana jubata participation in vegetation cover of the different regions were revealed.