Популяции редких видов растений на границе ареала на Среднем Урале

Abstract

Summary. The populations of two model species in extra-zonal habitats were examined. Oxytropis spicata is mountain-steppe endemic of the South Urals hardly spreading onto the Middle Urals, and Stipa pennata is widespread steppe species. The studied populations are located at the north limit of species ranges and situated in latitude gradient across two vegetation zones (foreststeppe and boreal). Cleared that the further north the lower are values of base features, both vegetative and generative, of mean-age individuals those are the main group providing a population reproduction. In the bounds of boreal zone the populations are noted with low values of base demographic parameters as follows numbers, density, vitality index. In the most northwards populations it is noted the value decrease in base countable and linear features of mature generative individuals.