Print PageThe phylogenetic structure and distribution of functional traits among plant species in a community provide insights into community assembly processes. These insights, however. are sensitive to the spatial and temporal scale of analysis. Here we use spatially-explicit, neighborhood (~ 20 m) models of tree and sapling growth and survival for 19 tree species across two census intervals, a highly-resolved molecular phylogeny, and information on eight functional traits to quantify the relative efficacy of functional similarity and shared ancestry in describing the effects of spatial interactions between tree species on demographic rates as the forest recovers from hurricane disturbance. We also assess the congruence of these results with observed phylogenetic and functional community structure in the neighborhoods of surviving live trees and those that are dead at the end of the census intervals.
Results/Conclusions
We found strong support for models in which the effects of spatial neighborhood interactions on tree and sapling growth and survival were scaled to species-specific mean functional trait values (e.g., wood specific gravity, leaf succulence, maximum height) but not to phylogenetic distance. The importance of functional trait similarity in mediating neighborhood interactions, however, differed between census intervals likely resulting from changes in community structure and composition as the forest recovered from hurricane disturbance. The weak phylogenetic signal in functional trait data allowed us to independently interpret the static neighborhood functional and phylogenetic patterns. We observed greater functional trait similarity in the neighborhoods of live trees compared to those of dead trees. This result suggests that competitive interactions among species were playing a limited role at the time of these censuses. The major force structuring this tropical tree community at these life history stages appears to be environmental filtering
