On the structure of populations of rare steppe plant species under anthropogenic pressure (Middle and Lower Volga region)

Abstract

Abstract In the article the population structure of 20 rare representatives of flora of the Middle and Lower Volga region (European part of Russia) is considered. Methods of population-ontogenetic direction were used during the work. Data on cenopopulations were obtained by medium- and long-term monitoring. The structure of cenopopulations of 20 species was studied: Ajuga chia Schreb., Artemisia salsoloides Willd., Artemisia santonica L., Artemisia taurica Willd., Astragalus cornutus Pall., Astragalus temirensis M. Pop., Astragalus zingeri Korsh., Atraphaxis frutescens (L.) C. Koch., Cephalaria uralensis (Murr.) Schrad. ex Roem. et Schult., Clausia aprica (Steph.) Korn.-Tr., Halocnemum strobilaceum (Pall.) M. Bieb., Hedysarum gmelinii Ledeb., Hedysarum grandiflorum Pall., Hedysarum razoumovianum Fisch. et Helm, Medicago cancellata Bieb., Oxytropis floribunda (Pall.) DC., Oxytropis hippolyti Boriss., Polygala sibirica L., Silene cretacea Fisch. ex Spring., Rindera tetraspis Pall. It was established that population characteristics of many rare representatives of the steppe flora of the Volga region are similar and depend on the type and duration of ontogenesis, life strategy and intensity of anthropogenic pressure on the places of growth.