Phylogenetic and Functional Alpha and Beta Diversity in Temperate and Tropical

42 The study of biodiversity has tended to focus primarily on relatively information poor 43 measures of species diversity. Recently, many studies of local diversity (alpha diversity) 44 have begun to use measures of functional and phylogenetic alpha diversity. Investigations 45 into the phylogenetic and functional dissimilarity (beta diversity) of communities have 46 been far less numerous, but these dissimilarity measures have the potential to infer the 47 mechanisms underlying community assembly and dynamics. Here we relate levels of 48 phylogenetic and functional alpha diversity to levels of phylogenetic and functional beta 49 diversity to infer the mechanism or mechanisms responsible for the assembly of tree 50 communities in six forests located in tropical and temperate latitudes. The results show 51 that abiotic filtering plays a role in structuring local assemblages and governing spatial 52 turnover in community composition and that phylogenetic measures of alpha and beta 53 diversity are not strong predictors of functional alpha and beta diversity in the forests 54 studied. 55 56