Ecological-floristic characteristics of the specially protected natural area «Kostinskie Loga» (Samara Region)

The paper considers ecological-floristic characteristics of the specially protected natural area «Kostinskie Loga», located in the southern part of the Samara Region (Bolshechernigovsky and Bolsheglushitsky Districts). The research area belongs to the subzone of fescue-feather grass steppes. The flora is represented by 240 species of vascular plants belonging to 160 genera, 49 families, 2 classes and 1 division. Ecological-cenotic analysis was used to assess the ecosystem diversity of the nature sanctuary. The leading groups for phytocenotic affinity are identified: steppe (65 species; 27,1%) and meadow-steppe (54 species; 22,5%), which indicates a good preservation of steppe biomes and demonstrates landscape features of the nature sanctuary. The low value of the synanthropization index (15,8%) reflects a moderate level of anthropogenic load. The adventive component of the flora is represented by 30 plant species (12,5%), among which the degree of naturalization is dominated by epecophytes (10,8%), the time of introduction – by neophytes (6,7%), the methods of introduction are dominated by xenophytes (27 species; 11,3%). The analysis of flora identified 6 species included in the «Black book of Central Russia» (Acer negundo, Atriplex tatarica, Cyclachaena xanthiifolia, Hordeum jubatum, Elaeagnus angustifolia, Xanthium albinum). The introduction of alien plants into natural communities occurs due to pasture digression in areas bordering the territory of the nature sanctuary. In general, the degree of anthropogenic transformation of the flora in most of the territory is expressed slightly, the vegetation cover retains natural features inherent in the steppe zone. A high degree of preservation of steppe communities with a significant participation of rare representatives of flora (14,6%) creates prerequisites for the organization of one of the steppe reserve sections of the Samara Region.