TABLE 3.

Comparison of numbers of known species in biodiversity hotspotsa

ContinentBiodiversity hotspotNo. of plant speciesNo. of terrestrial vertebrate speciesNo. of microbial species
South AmericaTropical Andes45,0003,38931
North AmericaMesoamerica24,0002,85955
Asia-PacificSundaland25,0001,80034
Europe and Central AsiaMediterranean Basin25,000770314
South AmericaAtlantic Forest20,0001,66848
Mainland AsiaIndo-Burma13,5002,185138
North AmericaCaribbean12,0001,51841
Mainland AsiaMountains of southwest China12,0001,141121
AfricaMadagascar and Indian Ocean islands12,0009875
South AmericaBrazilian Cerrado10,0001,26838
  • a For geographical definitions of biodiversity hotspots, see www.biodiversityhotspots.org/xp/Hotspots. Many of these hotspots do not conform to geographical boundaries. Portions of countries may be included, or, alternately, different locations in one country may belong to two or more hotspots. For the purposes of this comparison, if a country is part of a hotspot, its entire microbial count is listed, except in the United States, where the microbial count is listed by state.