Generic Spectrum in the Analysis of Flora in Samara-Ulyanovsk Volga Region
Consideration of the generic spectrum of flora is one of the elements of a general analysis of the flora of the study area. It allows to identify individual traits to a greater extent than the analysis of the family spectrum. The study of phytodiversity at the level of floras will allow in the future to clarify the patterns of their territorial location. Samara-Ulyanovsk Volga region is the territory within two administrative regions (Samara and Ulyanovsk) belongs to the Middle Volga region. It is very diverse in natural conditions. The generic spectra of the floras under consideration were constructed on the basis of a set of floristic descriptions which are grouped according to their affiliation to the physical-geographical units (12 districts and 4 provinces) according to the regionalization of A. V. Stupishin. We used about 400 floristic descriptions. Flora of the Sokskiy sublime-flat forest-steppe physiographic region with ridge relief is considered in more detail. This paper consideres five sample plots, the species composition of higher vascular plants which characterizes the local features of the areas in which they are described. These sites are located in the mouth of the Sok River, middle course, at the source, in the northern part of the district and the southeast part. The leading genera for the flora of the territory of Samara-Ulyanovsk Volga region are the following: Carex, Galium, Potentilla, Artemisia, Astragalus, and the genus Salix. It is shown that the first place in the generic spectrum is determined after 1000 species in the floristic list and is occupied by the genus Carex. The generic spectrum (in comparison with the family one) is able to reveal in more detail the individual features of the studied floras. This is manifested both in the mutual arrangement of the leading genera (with the exception of the first place) and in the appearance at the head of the spectrum of secondary genera. It was shown that at the level of the generic spectrum, the type of flora is determined by the number of the Astragalus and Potentilla genera.