Biodiversity at country level

Country level
biodiversity, represented by an index based on species diversity in the four
terrestrial vertebrate classes and vascular plants, adjusted according to country
area. Countries at the high end of the scale have a higher value of the index
than would be expected on area alone. The index is unreliable for smaller countries
(such as Togo and Luxembourg in this plot). Note: to reduce ambiguity Alaska
(USA) has for the purposes of this map been assigned to the same class as adjacent
Canada rather than the conterminous USA.
Source: based on national biodiversity indices developed by UNEP-WCMC.