Community phylogeny of the globally critically imperiled pine rockland ecosystem

Premise of the study: Community phylogenetic methods incorporate information on evolutionary relationships into studies of organismal assemblages. We used a community phylogenetic framework to investigate relationships and biogeographic affinities and calculate phylogenetic signal of endemism and invasiveness for the flora of the pine rocklands, a globally critically imperiled ecosystem with a significant portion of its distribution in South Florida, United States. Methods: We reconstructed phylogenetic relationships of 538 vascular plant taxa, which represents 92.28% of the vascular flora of the pine rocklands. We estimated phylogenetic signal for endemism and invasiveness using phylogenetic generalized linear mixed models. We determined the native range for each species in the dataset and calculated the total number of species sourced from each region and all possible combinations of these regions. Key results: The pine rockland flora includes representatives of all major vascular plant lineages, and most species have native ranges in the New World. There was strong phylogenetic signal for endemism, but not for invasiveness. Conclusions: Community phylogenetics has high potential value for conservation planning, particularly for fragmented and endangered ecosystems like the pine rockland. Strong phylogenetic signal for endemic species in our dataset, which also tend to be threatened or endangered, can help to identify species at risk as well as fragments where those species occur highlighting conservation priorities. Our results indicate, at least in the pine rockland ecosystem, no phylogenetic signal for invasive species, and thus other information must be used to predict the potential for invasiveness.