Floristic areas of the Middle Volga region: materials to the analysis

The publication presents some quantitative characteristics of the 17 pre-selected floristic areas of the Middle Volga region (the total number of species, number of indigenous taxa and the number of differentiating species). Based on the available data, a linear regression is constructed, illustrating the relative dominance of allochthonous or autochthonous trends in the development of flora in the selected areas. The cluster analysis of the species lists of the floristic areas was completed, and then DCA-ordination of the selected areas was implemented. It is revealed that the forest-steppe areas of the Cis-Volga and Trans-Volga regions are situated by the level of species richness, and the number of species in the selected floristic areas is increasing from West and East towards the Volga.