Figure 3. Richness center overlap.

Richness center overlap of four key focus groups—amphibians, birds, mammals and vascular plants. A richness center is defined as the top 6.4% of grid cells for each taxonomic group (see Materials and Methods for details). 4 groups = area where richness centers for all four groups overlap; 3 groups = richness centers for three groups overlap; 2 groups = richness centers for two groups overlap; 1 group = richness center for just one group occurs; 0 = richness center for none of the four groups.