Résumé
Darwin was one of the first to hypothesize a connection between niche
differentiation and competition and species relatedness, offering an
appealing framework to disentangle the processes involved in community
assembly based on their phylogenetic structure. Community assembly is,
however, the result of several processes, including potentially
confounding factors associated with dispersal limitations and spatial
effects, casting doubt about the application of phylogenetic diversity
metrics to infer community assembly processes. We implemented a
spatially-explicit model involving limited dispersal, drift, trait-based
selection, and competition to simulate community composition under
competing assembly processes in a landscape with contrasted habitat
connectivity. Our results formalize the idea
that habitat selection and limiting similarity leave a
significant signature in the phylogenetic structure of communities. We
identify the phylogenetic diversity metrics that best perform to retrieve
community assembly processes, but raise caution regarding their
interpretation, which can be misleading due to spatial effects.