Phytogeographical features and state of steppe communities of Mongolia (on the example of the model range "Mandalgobi")

Under conditions of climate change and intensive anthropogenic pressure, the cenotic diversity of steppe ecosystems is in constant dynamics. The definition of its current state will allow us to further consider the patterns of development of communities, assess the course and direction of the succession processes. This article describes the results of geobotanical studies of steppe ecosystems of the arid climate zone of Mongolia as an example of the research model polygon "Mandalgobi". Using the cluster analysis of cenoflor, a classification of the vegetation of the studied territory. On the basis of the dominant-determinative of the principle allocated to 2 groups of formations, desert steppe, including 5 of 12 formations and associations. Using the methods of direct and indirect ordination, the relationship between plant communities and environmental conditions is revealed. The obtained ordinational scheme confirms the objectivity of selection of syntaxons. As a result of the study of communities, it was noted that with increasing pasture load and increasing aridity of the climate, phytocoenotic diversity is reduced, native substitution is replaced and invasive species are introduced leading to transformation of plant communities, namely, a decrease in the share of forage crops, an increase in Allium polyrrhizum, capable of dislodging other species, as well as the appearance of digression species.