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

Abstract

AbstractQuestionIt is often assumed, but poorly tested, that patterns of phylogenetic diversity reflect functional diversity in plant communities. 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 strategies and competitiveness‐related traits.LocationCentral Europe, Belgium and the Netherlands.MethodsWe 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 representing niche preferences, dispersal strategies and competitiveness.ResultsWe 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.ConclusionsWe suggest that the combination of multiple trait states that co‐exist 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 some facets of functional diversity, the phylogeny–function relationship may not apply at all.