Climate and Species Richness Predict the Phylogenetic Structure of African Mammal Communities

We have little knowledge of how climatic variation (and by proxy, habitat variation) influencesthe phylogenetic structure of tropical communities. Here, we quantified the phylogeneticstructure of mammal communities in Africa to investigate how community structurevaries with respect to climate and species richness variation across the continent. In addition,we investigated how phylogenetic patterns vary across carnivores, primates, and ungulates.We predicted that climate would differentially affect the structure of communitiesfrom different clades due to between-clade biological variation. We examined 203 communitiesusing two metrics, the net relatedness (NRI) and nearest taxon (NTI) indices. Weused simultaneous autoregressive models to predict community phylogenetic structurefrom climate variables and species richness. We found that most individual communities exhibiteda phylogenetic structure consistent with a null model, but both climate and speciesrichness significantly predicted variation in community phylogenetic metrics. Using NTI,species rich communities were composed of more distantly related taxa for all mammalcommunities, as well as for communities of carnivorans or ungulates. Temperature seasonalitypredicted the phylogenetic structure of mammal, carnivoran, and ungulate communities,and annual rainfall predicted primate community structure. Additional climate variablesrelated to temperature and rainfall also predicted the phylogenetic structure of ungulatecommunities. We suggest that both past interspecific competition and habitat filtering haveshaped variation in tropical mammal communities. The significant effect of climatic factorson community structure has important implications for the diversity of mammal communitiesgiven current models of future climate change