Figure 2 . Response of tree diversity to the precipitation (mean annual precipitation; mm) gradient for native species, i.e., relatively uninvaded plots (a-f) and both native and alien species, i.e., highly invaded plots (g-l), across three main Hawaiian islands. Diversity is estimated for taxonomic, phylogenetic and functional diversity. Native species analysis includes 79 species and 282 plots. Native and alien species analysis include 142 species, where 63 are alien, and 375 plots. Diversity metrics are calculated based on Hill number, where, q=0 is richness of species, clades and functional groups and q=2 is evenness for species, clades and functional groups.