Assessment of the status of a rare species Oxytropis trichophysa bunge (Fabaceae) coenopopulations in Southwestern Tuva

The article presents the results of studying the biological features and demographic structure of populations of the rare species Oxytropis trichophysa. The results our studies showed that O. trichophysa is a cryophyte steppe species. It has strict ecological and coenotic habitat conditions, which are confined to the specific cryophyte steppe with dominated Oxytropis trichophysa, Festuca tschujensis, Artemisia frigida at the altitudes of 2000 m above sea level. The ontogenesis and ontogenetic structure of the endemic rare species O. trichophysa were studied in southwestern Tuva. The onthogenesis of this species is simple, incomplete, includes 4 periods: latency, pregenerative, generative and postgenerative and 8 ontogenetic stages. As a result, ontogenetic structure of various cenopopulations was revealed. All studied coenopopulations O. trichophysa are not complete, definitive, normal, mature, have a bimodal age spectrum with peaks at g1- and g3-individuals. High real seed production and a long generative period provide self-maintenance of O. trichophysa populations in extreme conditions of high-altitude steppes. It needs protection because of the small size of the populations and the narrow-local ecologo-cenotic confinement. Protection of Oxytropis trichophysa in Southwestern Tuva is considered to be necessary.