Refugium role of natural-territorial complexes of Samara Oblast (south-east of European Russia) in the conservation of petrophytic flora and vegetation

Abstract

Abstract Soils in the Samara Oblast are dominated by chernozems, so significant areas are allocated for arable land. Because of this, many natural complexes in leveled areas have been lost in the last 50 years. The preserved steppes on the slopes of river valleys and ravines are of scientific value. Petrophytic communities with unique flora are widespread here. We set a goal to study the petrophyte flora and vegetation on the territory of some natural monuments of regional importance in the High Zavolzhye (within the Samara oblast). The objectives of the study were: to analyze natural monuments of the Samara oblast for the presence of petrophytic flora and vegetation; to identify rare petrophytic species that are refugia flora; to study the biology and ecology, as well as structural features of their populations. According to the results-studied the flora and vegetation of 28 natural monuments of regional importance in the High Zavolzhye region. These natural sites contain up to 27% of rare petrophyte species and are flora refugiums. The status of 24 species in the region is evaluated. The results of studying the biology and ecology of rare species, as well as the structural features of their populations indicate the need to change the rarity category of some of them in the Red Book of the Samara oblast. In the territory of Samara Zavolzhye and Predovolzhye, their numbers and habitat continue to decrease, including Eriosynaphe longifolia, Trinia hispida, Diplotaxis cretacea, Matthiola fragrans, Dianthus leptopetalus, Astragalus sulcatus, Astragalus temirensis, Nepeta ucranica, Polygala sibirica, Atraphaxis replicata, Asperula petraea, Ephedra distachya.