Global Species Richness and Rarity
Global measures of the total number and the geographic restrictedness of species at 110km resolution. Calculated using species expert range maps.
Taxonomic Scope: Amphibians, Birds, Mammals, Reptiles, Turtles, Marine Fishes, Cacti, Conifers, Butterflies, Ants,
Spatial Extent: Global
Resolution: 110km
Source
Map of Life
Data Description
These layers display global species richness and rarity patterns for a range of vertebrate, invertebrate, and plant taxonomic groups. These patterns are based on sets of species level expert range maps. The spatial resolution (here 110km) is the finest that is scientifically sound for this data type (see Hurlbert & Jetz, PNAS 2007).
Species Richness
Richness describes the number of different species predicted to be inhabiting each cell in the map.
Species Rarity
Total rarity is calculated as the count of species predicted to be inhabiting a cell weighted by their respective range proportion in that cell. A species whose entire range is within the cell is therefore given a weight of 1, while a species who has only 1% of their range within the cell is given a weight of 0.01, and so on. Average rarity is the total rarity value divided by the total number of species within the cell.
