Differentiation of ecological groups of species according to their reaction to moisture in differentiation of steppes of the West Siberian plain and Southern Urals

Abstract

In a study of geobotanical releves of xeric meadows and steppes of the Southern Urals, ecological groups of plants are differentiated on the basis of their reaction to the moisture factor. An analysis of species activity index along the moisture gradient allows us to identify plant species that are diagnostic for zonal types of steppes: meadow steppes (order Festucetalia valesiacae) and typical bunchgrass steppe (order Helictotricho-Stipetalia). Most plants have similar activity indexes both on the West Siberian plain and in the Southern Urals. The regional differences were caused by geographic peculiarities of the habitats, namely petrophytic species are common in Southern Ural mountain landscapes and halophytic and sand species are common on the West Siberian plain.