Trends of some rare flora species populations in the Southern Urals foothills (Orenburg Region)

Abstract

The results of long-term (1994-2018) studies of the distribution and abundance of rare plant species in the foothills of the Southern Urals in order to identify their spatial and temporal trends are discussed. Some species retains its low numbers; in some species the number of populations and their amount were reduced, and some, probably, entirely disappeared from the flora. It is a new species in the local flora - Bupleurum aureum , but its low number does not allow to assess objectively its status and the necessary measures of protection. Spreading of Epipactis helleborine is also sporadic. The population of Veratrum lobelianum is gradually spreading to the South due to mesophytization of the climate and changes in pasture load on meadow and meadow-steppe ecosystems. The populations of the Cicerbita uralensis and Lathyrus litvinovii are in the critical condition. Thus, the change in environmental conditions leads to the fact that simultaneously with the reduction of the rare fraction, some species that previously had a small number, begin resettlement, contributing to the change in the appearance of the vegetation cover of the southern Urals foothills.