Is phylogenetic diversity a good proxy for functional diversity of plant communities? A case study from urban habitats

Question: It is often assumed, but poorly tested, that patterns of phylogenetic diversity reflect 'v sity plant curnnrurlifies. Here we test whether phylogeny can be used as a proxy for functional diversity in general and specifically for diversity in plant niche preferences, dispersal strategics and competitiveness-related traits. Location: Central Fu rope,Belgium and the Netherlands. Methods: We used a species composition data set from seven urban habitats, each sampled in 32 large cities of ten countries, and combined this with information about species phylogeny and functional traits, the latter divided into categories representingniche preferences, dispersal strategies and co SS Results: We found positive significant, yet very weak, relationships between phylogenetic diversity and overall functional diversity, and between phylogenetic diversity and diversity in both species dispersal strategies and competitiveness. The relationship between phylogenetic diversity and diversity in species niche preferences was not significant. Conclusions: We suggest that the combination of multiple trait states that coexist in urban plant communities and even within the same lineages weakens the phylogeny function relationship. Phylogenetic diversity is a weak proxy for functional diversity of urban plant communities. For sonic facets of functional diversity, the phylogeny function relationship may not apply at all.