On the dynamics of the ontogenetic structure of Astragalus henningii (Stev.) Klok. cenopopulations. (steppe Trans-Volga region)

Data on the ontogenetic structure of natural cenopopulations of the rare species Astragalus henningii (Stev.)Klok. on the territory of the Samara steppe Trans-Volga region are presented. Ontogenetic spectra have been determinedfor 35 cenopopulations on the territory of natural monuments of regional significance in the Samara region (Koshkinskaya Balka, Balka Kladovaya, Kostinskye loga, Gryzly, Mulin dol). The basic ontogenetic spectrum of cenopopulationsis one-vertex right-modal, the absolute maximum in it is represented by old generative individuals (35.7 %). The ontogeny of the species is at least 20 years, the longest in terms of time are the mature generative – 6–9 years and the old generative – 5–8 years.