Questions considered: 1. How is the structure of dominance in grass communities different with different models of organization? 2. How does the relationship between the degree of domination and species wealth differ in coenoses organized in different ways? 3. What are the reasons for this connection in the plant communities of these types? 4. What are the regional implications of the impact of dominants on the micro-sites of communities? The objects of research were: 1) communities of low mountain, subalpine and alpine meadows, steppes, subalpine swamps, alpine carpets and heathlands, grass tier of forests, pastures, river banks, trampled and ruderal habitats, and others; 2) areas of vegetation, including communities of different types. Species richness and relative abundance of species were estimated in plots 0.25 m². Abundance of the species was estimated through their fresh mass. The coenotic diversity of vegetation areas was assessed by identifying community types based on combinations of diagnostic species.

Aims. To make adjustments to the higher classification units of segetal vegetation of the Crimean peninsula based on the application of cluster analysis and modern conceps of syntaxonomy. Materials and methods. The analysis is based on 2876 own descriptions made in 1993-2011, 748 descriptions from the phyto-coenotic base of Flora and Vegetation Department of the Nikita Botanical Gardens, compiled in the 1960-1970s, and the descriptions from other literature sources. Results.The results of segetal vegetation studies of annual (cereal and tilled crops) and perennial (vineyards, orchards, plantations of essential-oil rose and lavender) of arable lands of the Crimean peninsula are presented. On the basis of the analysis the differentiation of communities on agrocoenotific gradient has been performed. Changes have been made to the classification scheme at the level of classes and orders. Crimean weedy communities are united in 51 associations, 15 alliances, 7 orders and 4 classes (Stellarietea mediae, Artemisietea vulgaris, Sisymbrietea, Oryzetea sativae).

The results of a geobotanical survey of meadow vegetation in the Valdaiskiy National Park (Novgorod region) are presented. In accordance with the floristic classification it has been established that the meadows of the region belong to the class of European mesophilic meadows Molinio-Arrhenatheretea . Two associations were revealed. In the floodplains of rivers and streams, communities of wet meadows of the association Lysimachio vulgaris-Filipenduletum ulmariae are common. It belongs to the alliance Filipendulion ulmariae of the order Filipendulo ulmariae-Loletalia uliginosi . On river terraces and watersheds, communities of the association Anthoxantho odorati-Agrostietum tenuis , belonging to the alliance Cynosirion cristati of the order Arrhenatheretalia , are developed. The significant importance of the meadows for the conservation of natural biodiversity and cultural heritage of the Novgorod region is noted.

The variety of the vegetation cover of the northern part of the coast of Heracleisky peninsula was studied. Prodromus includes 6 classes ( Festuco-Puccinellietea, Crithmo-Staticetea, Cakiletea maritimae, Therosalicornietea, Juncetea maritimi, Phragmito-Magnocaricetea ), 7 orders, 9 unions, 10 associations, 2 subassociations and a variant of association. The new association Bassio prostratae-Elytrigietum obtusiflorae and the new variant of association Salicornio-Puccinellietum giganteae var. Plantago coronopus described in the class Festuco-Puccinellietea.

The first soil classifications dividing soils according to their individual properties and reflecting the resource value of soils were, in fact, substantive classifications. The appearance of soil science that studies soils as special natural bodies changing in space according to natural laws has led to the emergence of genetic soil classifications. The most detailed multilevel Classification of soils of the USSR (1977) is ecological genetic classification based on the relationship between soils and soil formation conditions, where the type of vegetation cover is the top hierarchy level. With the development of soil science, inconsistencies between the genetic classification and the growing volume of knowledge, difficulties in its formalization, and contradictions with the zonal approach have appeared. A paradigm of substantive classification has emerged based on modern measurable morphological and analytical indicators of soils. It is most fully implemented in the World reference base for soil resources (WRB); a compromise option is the substantive- genetic Soil Classification of Russia (2004). In these classifications, for the first time soils with strong human influence (Antrosols and Technosols) are included at a high classification level. The tasks of substantive classifications are the certainty of soil identification; however, discrete classification cells with tight boundaries do not correspond to the continual nature of soils. When using WRB 2014, geobotanical studies receive a certain “freedom” from soils, at the same time, the rigid framework of the parameters of soil properties makes it possible to more accurately identify soil-depended condition of the vegetation cover.

The article analyzes the syntaxonomic structure of the steppe communities of the central foothill part of the Crimea. They belong to the class Festuco-Brometea Br.-BI. et R.Tx., two orders, two unions and two sub-unions, five associations. For coenoflora at the level of associations of ecological-floristic classification, a detailed systematic, arealogical, ecological-biomorphological analysis was carried out for the first time. The most significant differences in the structure of the communities of steppe vegetation described on the basis of ecological-floristic classification are revealed. Significant participation in the formation of communities of species of Mediterranean origin and shrubs has been established. Moreover, unlike the rest of the communities, the associations of Asphodelinetum tauricae Didukh 1983 association are characterized by the dominance of these floral elements in their structure. The steppe communities of the studied region are characterized by significant xerophytization of the vegetation cover.

The analysis of modern state of boreal larch forests in their main part of range placed in continental bioclimatic sector of Northern Eurasia (Siberia and continental part of Russian Far East) was performed. Conspectus of larch forests syntaxa was developed and it includes one class - Vaccinio myrtilli-Piceetea abietis Br.-Bl. in Braun-Blanquet et al. 1939, one subclass - Laricenea cajanderi-sibiricae subclass nova hoc loco, two orders - Ledo-Laricetalia cajanderi Ermakov in Ermakov et Alsynbayev 2004, Lathyro humilis-Laricetalia cajanderi Ermakov, Cherosov et Gogoleva 2002, six alliances - Ledo palustris-Laricion cajanderi Ermakov in Ermakov et Alsynbayev 2004, Pino sibiricae-Laricion sibiricae Ermakov in Ermakov et Alsynbayev 2004 (syn. Pino sibiricae-Laricion sibiricae Guinochet ex Dostalek et al. 1988 nom. nud., art. 2b, art. 8, Barkman et al., 1976, art. 2b, art. 8, Weber et al., 2000), Cladonio stellaris-Laricion gmelinii Anenkhonov et Chytry 1998, Empetro-Piceion obovatae Morozova in Morozova et al. 2008, Aulacomnio acuminati-Laricion cajanderi Ermakov Cherosov et Gogoleva 2002, Rhododendro daurici-Laricion gmelinii Ermakov in Krestov et al. 2009 and 30 associations. Diagnostic features of all syntaxa and their main ecological characteristics were represented. The problems of larch forests classification and syntaxa nomenclature were discussed. All diversity of boreal light-coniferous deciduous (larch) forests of continental bioclimatic sector of Northern Eurasia of the class Vaccinio-Piceetea was included in new subclass Laricenea cajanderi-sibiricae subclass nova hoc loco. Diagnostic species combination of the subclass includes predominating larch species ( Larix cajanderi, L. sibirica, L. gmelinii, L. decidua, L. olgensis ) and diagnostic species of the subordinated orders Ledo-Laricetalia cajanderi and Lathyro humilis-Laricetalia cajanderi .

Goal. To analyze the current state of the Crimean pine forest communities and give a forecast of possible changes in the trend of global climatic changes. Materials and methods. The object of research is phytocenosis (nomenclature description of the association), described in the Yalta Amphitheater at an altitude of 1000 m above sea level. The packing density of species on gradients of environmental factors was calculated using the original Pover program. Unified information on the distribution of plant species along gradients of factor conditions and resource factors (illumination-shading, thermal mode, cryo mode, humidification, moisture variability, substrate acidity, salt regime (anionic composition), carbonate content, nitrogen content, particle size distribution (mechanical) composition (porosity) of the substrate) was obtained from the Ecodata database. Results. The community will become most vulnerable when the cenotic factor “lighting-shading” changes with a significant decrease in the amount of light entering the day surface. Succession rearrangements of phytocenoses can cause an increase in the average July temperature by 2.4 degrees, exceeding the tolerance level for a given phytocenosis. Other environmental factors and resource factors have a significant margin of safety.

Data on the state of bottom vegetation and biotopes of marine protected areas (MPA), which are part of six specially protected natural areas (SPAs) of Sevastopol, are presented. Based on a synthesis of hydrobotanical studies for 2008-2018, the composition and structure of Cystoseira and Phyllophora phytocenoses, key for the coastal zone of the southwestern Crimea and the Black Sea ecosystem, are characterized; their species diversity, production indices, and distribution features are described. A comparative analysis of long-term changes showed that in the structure of the Cystoseira phytocenosis of MPAs there was an increase in the number of green algae, indicators of household pollution, the lower boundary of the distributions of both phytocenoses was halved. For the first time for the Sevastopol region, data are presented on the area of Cystoseira and Phyllophora biotopes, which amounted to 3323.5 and 430.5 ha, respectively (9 and 17.3% in the areas of protected areas). Scientifically based recommendations for the conservation and restoration of phytocenoses and biotopes of key species with high conservation status are proposed.

A comparative analysis of the vegetation composition in the meadow steppe community and the meadow in the middle in a karst sinkhole was made. The appearance of the meadow, which is formed by its coenogenous elements, is contrasted with the steppe. The compositions of the elements in two neighboring coenoses are also not similar. Obviously, the examined communities have different genesis. These differences are due to environmental conditions of karst depression. Yaila meadows are here indigenous primary vegetation of azonal origin.

The aim of the work is to revise the prodrome and diagnostic species of the classes of natural dry grassland and phrygana vegetation of the Southern Crimea based on own field studies and modern literature data. Methods. The work is based on the Braun-Blanquet approach to classification of vegetation communities. Higher syntaxonomy units and lists of diagnostic species are given in accordance with “Vegetation of Europe ...” (EuroVegChecklist), nomenclature of syntaxon according to the requirements of the “International Code of Phytosociological Nomenclature”, nomenclature of taxon according to the Catalogue of Life and Euro + Med PlantBase international databases. Results. A preliminary version of the prodrome of natural dry grassland and phrygana vegetation of the Southern Crimea has been compiled. It was established that this vegetation type includes communities of 12 classes: Sedo-Scleranthetea , Trifolio-Geranietea sanguinei , Festuco-Brometea , Festuco-Puccinellietea , Kalidietea foliati , Ononido-Rosmarinetea , Cisto-Lavanduletea stoechadis , Helianthemetea guttati , Stipo-Trachynietea distachyae , Saginetea maritimae , Asplenietea trichomanis , Drypidetea spinosae. There are 14 orders, 14 alliances and 30 associations, three of which need to be validated. The classes of rock and scree vegetation ( Asplenietea trichomanis , Drypidetea spinosae ) are described in most detail. For most classes, a significant part of the classification units has not yet been established. Conclusion. The preliminary prodrome of the natural dry grassland and phrygana vegetation of the Southern Crimea includes 12 classes, 14 orders, 14 alliances and 30 associations. A great part of syntaxa has not yet been established. The composition of the diagnostic species indicates a significant floristic proximity of the classes Sedo-Scleranthetea - Helianthemetea guttati - Stipo-Trachynietea distachyae , Festuco-Puccinellietea - Kalidietea foliati , Ononido-Rosmarinetea - Cisto-Lavanduletea stoechadis .

Until 1995, a special study of the flora and vegetation of Tuva agroecosystems was not carried out. This work is devoted to the research of features of overgrowth of abandoned arable land, species composition of vegetation, productivity, stages of healing and their duration, prospects of their use as forage lands. Purpose. To determine the main trends of fallow ecosystems in the course of succession: changes in the species composition of phytocenoses, a set of dominant species, ecological groups of plants, the structure of plant matter and primary products in different edaphic conditions, but in the same climatic zone. Methods. For the study of each succession, key sites on the initial (control) and successional ecosystems were selected, where changes in the species composition of communities, the composition of dominants, phytomass stocks and its structure were studied. The studies were conducted in the period 1997-2018. Results. In the sharply continental climate of Tuva, the development of agriculture without irrigation has not justified itself. In the 50-60 years of the last century there were periods of mass development of virgin lands. In the early 1990s, the area of land cultivated for cultivation began to decline sharply. It is shown that the fallow succession proceeds naturally and synchronously. Summary. In arid conditions of Tuva, the initial stage of succession (0-4 years) is weeds. The first intermediate stage (4-7 years) is marked on all deposits by the absolute dominance of wheatgrass and the appearance of dominants characteristic of a certain type of steppes. The second intermediate stage (7-11 years) is characterized in that all deposits are dominated by species of the original indigenous steppes. The late stage (11-20 years) is the phase of formation of terminal communities with characteristic sets of species for each steppe, including the dominant ones.

Purpose. Creation of a database of medicinal plants of the Republic of Tuva using geoinformation technologies. Methods. The objects of research are populations of wild medicinal plants growing in natural habitats. Research was carried out in the period 1996-2018. Data on medicinal plants, stocks of above-ground and underground phytomass, biological and operational reserves are stored in the PDF format of Adobe Acrobat 8.0. The main element of the database (DB) is the form and the table. All data is located in the table, the fields of which are displayed in the database form. Each entry refers to a particular type of a plant, and in the appropriate field are the characteristics. Results. The created computer scientific database "Medicinal plants of the Republic of Tuva" contains a systematic list of species of vascular plants of the flora of the Republic, which consists of 200 species. The GIS map "Medicinal plants of the Republic of Tuva" was created, where the software product ArcView GIS was used as the basis. Summary. The introduction of modern information technologies in the data collection process opens up new opportunities in biological and environmental research. The developed database can be used to study the characteristics of medicinal plants in different regions, to conduct a complete taxonomic and typological analysis of medicinal plants, to solve methodological problems in the study of plants, as well as for monitoring.

The aim of the article is to review the geographical distribution of the main types of plant communities of mires of the boreal zone of European Russia, and to assess the impact of the orographic factor on it. The review made on the materials of 40-year study of mires vegetation of European Russia. It was found that the main botanical and geographical boundaries within the taiga zone of European Russia pass through the subzones of the northern and southern taiga, the Eastern edge of Fennoscandia and the coastal part of the North-Western region.

In order to classify the vegetation, as well as its sozological assessment, based on the Brown-Blancke method, geobotanical descriptions of the vegetation of the spit and Tuzla island were carried out, rare species were noted, and a cartographic survey of the territory was carried out. As a result of five-year studies, the classification of vegetation of the spit and Tuzla island was made. 22 associations (2 new - Lactuco tataricae-Elaeagnetum angustifoliae and Gypsophiletum perfoliatae), 8 subassociations (6 new - Lactuco tataricae-Elaeagnetum angustifoliae juncetosum maritimae, L. t.-E. a.) are described. Artemisetosum arenariae, Phragmito-Juncetum maritimi puccinelietisum distantis, Cakilo euxinae-Crambetum artemisetosum arenariae, Cakilo euxinae-Lactucetum tataricae typicum, C. e.-L. t. gypsophiletosum perfoliatae, basal 2 community and 7 out of 13 classes and 14 unions. A geobotanical map of the spit and Tuzla island has been compiled. The high estimates of the environmental significance of observed association: Cakilo euxinae-Lactucetum tataricae, Eryngio maritimi-Cakiletum euxinae, Gypsophiletum perfoliatae and Elaeagnetum angustifoliae-Lactucetum tataricae. The necessary establishment of protected areas for the protection of some plant communities in the vegetation and the islands.

The paper presents the results of study the reproductive biology of a number of higher plants and shows the features of the formation of their generative structures, pollination, fertilization and seed formation. It has been established that the studied species have a high reproductive potential, they are characterized by the conjugacy in the development of male and female gametophyte and gametogenesis, the relationship and relevance of the development of flower elements and pollinating insects, etc. It is indicated that the limiting factors of high productive reproduction and reproduction of the studied plants are anomalies of the processes of formation of generative structures that occur during critical periods under the influence of extreme environmental factors, weak exchange of genetic information due to discontinuity of the area and small number of cenopopulations, as well as human impact. It is shown that the current state of natural cenopopulations of the studied rare species of the Crimean flora necessitates the development and strict observance of scientifically based measures for their protection.