Taxonomical features of the flora of the Irgiz physical-geographical region (Southern part of the Samara Trans-Volga region)

Abstract

The authors analyze flora taxonomic composition of the Irgiz physiographic region. It is located in the southern part of the Samara Trans-Volga region and belongs to the steppe natural zone. The climate here is drier than in other parts of the region. The main type of vegetation is steppes; forests occupy insignificant areas and are confined to floodplains. The area is characterized by a strong plowing of the territory. The authors register floras taxonomic features of the steppe regions in the Samara Trans-Volga region, and analyze the composition of family and generic spectra in comparison with the floras of the forest-steppe zone of the Samara and Ulyanovsk regions. The following results have been obtained: 1) the floras of the steppe regions correspond to the Fabaceae type with the predominance of the Astragalus genus in the Fabaceae family; the leading genera include Carex , Potentilla , Salix , Galium ; 2) a feature of the steppe zone is a high position in the spectrum of the genera Artemisia , Atriplex , Allium , in the family spectrum a high position is occupied by Chenopodiaceae, the Samara region, considered by us within the framework of the Irgiz physical and geographical region, is not completely uniform in natural conditions. Differences in natural conditions affect the species composition of vascular plants. Three local floras, geographically distant from each other within the region, are considered. The areas of the described floras differ from each other in relief. It is reflected in the occurrence of representatives of individual taxonomic groups. This determines the difference in the taxonomic parameters of the described local floras.