Historical Background of the Homogenization of Urban Floras of the Urals and Volga Region

One of the characteristic features of urban floras is their homogenization, which is synonymous with the loss of regionally unique species and a reduction in functional diversity. Here we examined the species composition of native and alien species in the flora of Russian cities to identify the contribution of these groups of species to the homogenization and differentiation of urban floras. The results we obtained showed that the species similarity of urban flora depends on the distance between cities—urban flora of geographically close cities have the lowest species dissimilarity. This distance-dependence is highest for neophytes dissimilarity and lowest for archeophytes dissimilarity. Thus, the homogenization of the species composition of the Ural and Volga region urban floras is provided mainly by archeophytes, while a group of neophytes increases the β-diversity of urban flora.