Nathan G. Swenson, University of Arizona
Background/Question/Methods The biological diversity of communities is promoted and maintained by ecological and evolutionary processes that operate on species attributes. The degree to which species diversity in communities changes under natural and disturbed conditions has been often analyzed. Despite this, temporal trends in the phylogenetic and functional diversity of communities, which may provide deeper insights into the mechanisms promoting species diversity and co-existence, have been less often quantified. This is particularly true in tropical tree communities where it has been difficult to quantify the species, functional and phylogenetic diversity of entire communities over long periods. Here I examine temporal trends in the species, functional and phylogenetic diversity in two Neotropical forest dynamics plots. In particular, in this talk I will assess: (i) whether these components of biodiversity are in equilibrium through time; and (ii) how have long-term climatic trends and forest disturbance histories altered the species, functional and phylogenetic diversity in these forests.
Results/Conclusions The results suggest that for the forests analyzed the three components of community biodiversity are not in equilibrium and that long-term directional trends in species, functional and phylogenetic diversity are closely linked to disturbance in these forests. Lastly, the results will be discussed with reference to mechanisms of community assembly, tropical forest dynamics and the promotion and maintenance of tropical forest biodiversity.