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.

The forest–steppe is considered as an integral geographical and ecological-phytocenotic zonal phenomenon of Northern Eurasia, which has its own characteristic features. The unique altitudinal zone of the forest–steppe is formed in the mountains of Siberia and occupies a certain place in the altitudinal-zonal spectra of the mountains. The structure of the oroboreal forest–steppe is considered on the basis of the ecosystem concept and an ecological–geographical approach to data interpretation. An exposed forest–steppe is a complex combination of plant communities of forests and steppes that occupy contrasting ecotopes within the same altitudinal level, forming a single indigenous altitudinal-climatic ecosystem, where its components closely interact with each other and with the surrounding natural conditions. The cenotic and biotic diversity of the forest–steppe is due to bioclimatic conditions that determine the hydrothermal areas of distribution of mountain formations and the composition of their climatypes. Characteristics of forest–steppe combinations of seven regional orobiomes of Siberia provide comparative information about the geography of mountain forest–steppe, the combination of forest and steppe communities, their composition and bioclimatic conditions of development.

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.

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.

An integral evaluation of the modern vegetation cover of the Stanovoy Highlands has been carried out on the basis of identifying priority ecological functions for vegetation communities in model sites of the mountain system (in the Upper Angara depression and in the North-Muya Range). Identification of the typological diversity of vegetation and the ecotopic relations of communities, conducted on the basis of field data and remote sensing data, made it possible to compile vegetation maps of model sites with the allocation of five priority ecological functions (permafrost-stabilizing, anti-erosion, anti-avalanche, drainage, water-regulating) for vegetation communities of different altitudinal belts (mountain taiga, sub-tundra, tundra belts). An analysis of the current state of vegetation has been done on the basis of changes in the forest area for the period from 2000 to 2018. Trends in the change of functions of communities have been determined. The ecological and geographical approach to determining the diversity of functions of the vegetation communities of the Stanovoy Highlands revealed the specifics of the botanical diversity of the mountain territory according to altitudinal and regional patterns. The mountain taiga belt is composed of vegetation communities (mainly larch forests) that perform a wide range of environmental priority functions in various ecotope conditions. Sparse forests and dwarf pine communities perform environmental protection functions in conditions of steeply sloping relief in the sub-tundra belt. High-mountain communities are characterized by a drainage function in the top levels of ranges in the tundra belt. The composed phytoecological maps of vegetation have made it possible to identify the spatial structure of the mountain biome on the example of model areas according to the actual dynamic of vegetation cover of the Stanovoy Highlands connected with cutting and fires. Approbation of the cartographic method in the study identifies the prospects for its use in ecological mapping with an evaluation of the functions of vegetation communities in mountain ecosystems.

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.

A regional assessment of the Crimean-Novorossiysk orobiome, which is considered a reference unit for the inventory and analysis of mountainous biodiversity, is based on the concept of ecosystem diversity. The altitudinal zonal structure of the vegetation cover is studied on the example of the Utrish–Tuapse geographic variant of the orobiome associated with the northwestern Caucasus, in accordance with which the spatial differentiation of flora and plant communities is formed. A quantitative substantiation of the biota and abiotic parameters characterizing the botanical and geographical uniqueness of the orobiome is given. The spectrum of altitudinal zonality of vegetation is determined, a quantitative assessment of floristic diversity by zones is given, and some features of the spatial structure of the diversity of communities in the mountainous area are shown.

The article presents the results of the assessment of the coenotic variety of forests of reference landscapes of glacial and water-ice genesis of the Moscow region in different physico-geographical regions, such as Verkhnevolzhskaya lowland, Klinsko-Dmitrovskaya range, Teplostanskaya Upland and Meshcherskaya lowland. The assessment basis was the vegetation map of the Moscow region (1 : 200 000) and space images of the Landsat system. A basic unit of assessment is epiassociation, which presents the ecological condition of the forest cover. It provides the possibility of using the ratio of indigenous, short-and long-term communities to determine the extent of human impact and forest ecological functions preservation. Based on the cartographic method of research, landscape complexes of forest types have been identified, and the ecosystem diversity at the local level has been assessed. The vegetation map of the Moscow region has been updated as a result. The authors found that in the landscape of Verkhnevolzhskaya lowland the main spaces are occupied by fir and pine short-term forests. The landscapes of the Klinsko-Dmitrovskaya range and Meshcherskaya lowland are dominated by coniferous forests; the Teplostanskaya Upland - by coniferous-deciduous forests. In all considered landscapes, the authors noted a strong reduction of forest cover. Primarily it is associated with the human impact increase on natural ecosystems. The strongest reduction in forest areas and forest cover fragmentation occurred in the landscapes of the Klinsko-Dmitrovskaya range and Teplostanskaya Upland. Reduction maps of forest cover of reference landscapes were compiled based on the data obtained.

The dynamics of the botanical diversity of plain forbs–bunchgrass steppes is analyzed for the period of 2008–2018 based on materials from the biomonitoring of plant cover at the Tumentsogt experimental station (Eastern Mongolia) as part of the scientific program of an integrated Russian–Mongolian biological expedition. Eight permanent test plots of 100 m2 were laid along the transect on the plain between hills in the northeastern part of the experimental station. We analyzed the correlation between the main parameters of the plant communities (the species composition, richness, and saturation; the height and abundance of species; and the density of grass stands) with the meteorological conditions (the heat supply and the amount and distribution of precipitation during the growing period). A combined analysis of phytocenotic and climatic data was performed with nonparametric multidimensional scaling of indirect ordination. Ecotopic fluctuations caused by changes in the amount and regime of precipitation in different years, as well as by the dynamics of the temperature regime, were studied. The species saturation of communities was maximal in years with low ombrothermic indices and lowest in years with high indices. The floristic composition of communities of three–feather-grass steppes includes a flora-cenotic core composed of 23 permanent perennial steppe and forest–steppe species, which provides a relative stability of ecosystems under changing environmental conditions. The dynamics of steppe ecosystems of the East Mongolian steppes is phytocyclic.

The aim is to introduce the concept of biogeographical map "Biomes of Russia" (m 1:.7.500000), scientific and methodological principles of the development of its content, the selection of indicators to characterize the biodiversity of the regional biomes and mark its place and role in the development of biogeography as well as biogeographical mapping and in terms of practical application as in education, in the sustainable development of the regions and for solving the problems in the field of nature and environmental protection.Materials and methods. Map is based on the classification of terrestrial ecosystems (biomes) and eco-geographical approach to their subordination on different levels of organization of the biotic cover.Results. We have displayed on the map the differentiation of the country on the composition of ecosystems and their biodiversity at the regional level. Biomes at the regional level are central to the study and are mapping units. Legend includes 35 lowland biomes and 31 orobiomes (in the mountains). A characteristic has been made up for each biome, which includes indicators of moisture and heat supply, the number of species of vascular plants, mosses and lichens, terrestrial vertebrates (mammals, birds, reptiles and amphibians). To illustrate this, there is the characteristic of the 3 orobiomes of the North Caucasus.Conclusion. Using biomes as supporting biodiversity accounting units enables the integrated analysis of botanical and zoogeographic information about biota, as well as the dual study of biotic and abiotic components of the ecosystem. The current state of biomes is defined by two interrelated processes of transformation and modification of ecosystems and the reduction or loss of biological diversity. Map of regional biomes can serve as a basis for further research on the biome biodiversity on species and ecosystem levels; as the inventory of the biota and the creation of databases on species and cenotic diversity of biomes; for the development and justification of environmental protection measures.

Stitchwort polster (Stellaria pulvinata Grub.) is an endemic species with local distribution in the arid regions of Central Asia—the Mongolian Altai highlands (2500–3800 m above sea level). This species forms an endemic alpine cryophyte-herb-polster formation that is divided into three classes and ten groups of associations. Stitchwort is dominant and codominant in cryophyte-herb polster communities. In cryophyte-herb-sedge-kobresia polster communities, this species changes its presence from significant to minor, with moderate abundance. Cryophyte-herb-gramineous polster communities are widespread and have the highest coenotic diversity. Cryopetrophyte polster communities with Stellaria pulvinata play an important role in the vegetation cover of the central part of Mongolian Altai. They do not form a separate high-rise belt but are found in the composition of the vegetation cover of two high-rise belts, the cryophype bunchgrass steppe belt (2800–3200 m) and the cryophyte kobresia and sedge tundra belt (3200–3500 m). They are also sporadically found in the subnival belt (3500–3800 m). At the level of microcombinations, the vegetation cover structure contains serial ranks of polster communities on the mountainsides and polster complexes with herb-gramineous communities on the peneplanation surfaces and alpine moraines. Exposition combinations of phytocatenae with cryophyte-herb polster communities and cryophyte-bunchgrass steppes with stitchwort occur at the level of meso-combinations.