Richness

rho = .826

Worldmap can also depict rarity by calculating a value for each cell consisting of the summed inverse range size for all species present in the cell.  For example, a species that occurs in only that cell contributes a value of “1,” whereas a species that occurs in 5 cells contributes a value of 1/5 to the overall value of each cell in which it occurs.  Because range size rarity is dependent upon total richness, it has been alternatively referred to as “endemism richness” (Kier & Barthlott, 2001).  For the 93 target species, inverse range size rarity is highly correlated with species richness (rho = .826).

Rarity (inverse
range-size)