Where is most of the biodiversity of the Earth located?

Even though they cover less than 10 percent of the planet's land surface, tropical rainforests contain more than half of all species. The rainforests of Central and South America, equatorial Africa and Southeast Asia are home to millions of species of plants and animals. Coral reefs, the "rainforests of the sea," are home to one-quarter of all marine life.
Deserts, prairies, wetlands, estuaries, ocean bottoms, mountain tops, temperate forests—even city parks, school yards, and backyards—are all home to diverse communities of plants and animals