The Global 200:
A Representation Approach to Conserving the Earth’s Distinctive Ecoregions
David M. Olson, Eric Dinerstein, Robin Abell, Tom Allnutt, Christopher Carpenter, Loren McClenachan, Jennifer D’Amico, Patrick Hurley, Ken Kassem, Holly Strand, Meseret Taye, and Michele Thieme
Conservation Science Program, World Wildlife Fund-US
1250 24th Street, NW, Washington, DC, 20037 USA
E-mail: email@example.com / firstname.lastname@example.org
Much conservation attention has focused on the preservation of tropical moist forests (rain forests) because they harbor an estimated 50 percent of species on Earth. However, a comprehensive strategy for conserving global biodiversity should strive to save the other 50 percent of the species and the distinctive ecosystems that support them. Tropical dry forests, tundra, temperate grasslands, lakes, polar seas, and mangroves all contain unique expressions of biodiversity with characteristic species, biological communities, and distinctive ecological and evolutionary phenomena. Some of these major habitat types (i.e., biomes), such as tropical dry forests and Mediterranean-climate shrublands, are on average more threatened than are tropical moist forests and require immediate conservation action.
To better incorporate representation of the Earth’s distinctive ecosystems in conservation strategies
, we conducted an analysis of ecoregions representing the Earth’s 30 terrestrial, freshwater, and marine major habitat types. Based on a comparative global analysis and synthesis of five extensive regional studies
, we identified 238 ecoregions as priority targets for conservation action because they harbor the most outstanding and representative examples of the world’s diverse ecosystems. These 238 ecoregions—the Global 200—are comprised of 142 terrestrial
, 53 freshwater
, and 43 marine
ecoregions. Selection of ecoregions was based on analyses of species richness, species endemism, unique higher taxa
, unusual ecological or evolutionary phenomena, and global rarity of major habitat types. We selected outstanding ecoregions within each major habitat type from each of the world’s biogeographic realms and ocean basins to better capture the variation in species assemblages around the world.