Challenging Urban Species Diversity: Contrasting Phylogenetic Patterns across Plant Functional Groups in Germany

Abstract

The high vascular plant species richness of urbanized areas in Germany is biased towards species with specific functional traits or trait states, and towards common species, as shown in the preceding chapters. The last aspect of species diversity to be analyzed here is phylogenetic diversity: In terms of species richness, an assemblage of three Poaceae species seems as diverse as an assemblage of one Poaceae, one Asteraceae and one Fagaceae species; but the former assemblage appears much less diverse when considering their phylogenetic background: The three Poaceae species belong to one family and are thus closer related to each other than the species from the three families of Poaceae, Asteraceae and Fagaceae. Phylogenetic diversity, which measures the diversity of evolutionary relationships between species, reveals these underlying patterns, and so provides valuable information for species conservation and about mechanisms of species assembly (Vane-Wright et al. 1991).