The influence of environmental factors on the composition of the petrophytic-steppe communities in the south of the Sverdlovsk and in the north of the Chelyabinsk regions

Abstract

The investigated petrophytic-steppe communities of the Middle Urals do not belong to the zonal vegetation type. Their growth in the region is associated with an unusual combination of environmental conditions - well-drained, well-heated rocky riverbank slopes of the southern and close exposures of slopes. The aim of the work was to identify the key environmental parameters that determine the composition and structure of petrophytic-steppe communities in the south of the Sverdlovsk and north of the Chelyabinsk regions. The communities of the coastal slopes of the Iset, Bagaryak, Patrushikha, Sysert and Neiva rivers were studied. An array of 74 geobotanical releves of communities from 8 plots was collected, considering environmental factors, and the composition and structure of plant communities on plots of 1 m2 were also detailed. Using the CCA method of ordination, the contribution of environmental parameters to the variation in vegetation cover characteristics was estimated. It was shown that the parameters characterizing the type of rocks, as well as indicators of the amount of precipitation, have the greatest contribution. Four variants of combination of species in the studied communities, gravitating to certain sets of environmental parameters, were identified, for each of the groups a stable composition of dominant species was noted, and species characterized by a high level of constancy were identified.