Journal of Vegetation Science 24 (2013) 877–889 SPECIAL FEATURE: FUNCTIONAL DIVERSITY Partitioning phylogenetic and functional diversity into alpha and beta components along an environmental gradient in a Mediterranean rangeland Maud Bernard-Verdier, Olivier Flores, Marie-Laure Navas & Eric Garnier Keywords Abstract Beta dissimilarity; Calcareous rangelands; Community assembly; Environmental gradient; Questions: To what extent is the functional structure of plant communities Functional traits; Phylogenetic community captured by phylogenetic structure? Are some functional dimensions better rep- structure; Trait phylogenetic signal resented by phylogenetic relationships? In an empirical study, we propose to test the congruence between phylogenetic and functional structure at the alpha and Nomenclature the beta scale along an environmental gradient. Bernard (1996) Location: Causse du Larzac, southern France. Received 1 April 2012 Accepted 12 December 2012 Methods: We measured species abundances and eight key functional traits in Co-ordinating Editor: Francesco de Bello 12 plant communities distributed along a gradient of soil depth and resource availability in a Mediterranean rangeland. A phylogenetic super-tree of the spe- cies was assembled, and after quantifying the degree of phylogenetic signal pres- Bernard-Verdier, M. (corresponding author, ent in each trait, we quantified taxonomic (TD), phylogenetic (PD) and
[email protected]): Universite´ functional (FD) diversity both within (alpha scale) and among (beta scale) com- Montpellier 2, Centre d’Ecologie Fonctionnelle munities, taking species abundances into account. We tested for trends in diver- et Evolutive (UMR 5175), 1919 route de Mende, sity along the environmental gradient, and looked for congruence among 34293 Montpellier, France different facets of diversity, both at the alpha and the beta scale.