Figure 4. Environmental predictors of phylogenetic structure in island floras.

Partial residual plots from averaged Generalized Additive Models illustrate the standardized effect size of phylogenetic diversity (PD_es) of angiosperms, palms and ferns as a function of environmental predictors. Models included spatial eigenvectors to account for spatial autocorrelation. Regression lines are shown if the variable was significant in the averaged model. In (a), PD_es was based on dated family-level phylogenies of angiosperms (orange) and ferns (blue). In (b), PD_es was based on dated genus-level phylogenies of palms (red) and ferns (blue). Only islands with at least two species of the focal group are shown (363 islands for all angiosperms, 71 for palms and 234 for ferns). MLSR = Mainland species richness, SLMP = surrounding landmass proportion, CCVT = Late Quaternary climate change velocity; Geologic island types: FR = continental fragment, OC = oceanic island, SH = continental shelf islands.