The desert biome is an ecosystem that forms Is formed by the dryness in the ground due to no rainfall for a long amount of time. Deserts cover about 20% of the Earth. There are four major types of deserts. Some deserts are hot and dry, some are semiarid, some are coastal, and some are cold. Not a lot of species. Low latitudes, and can be found in North-America, South-America, Africa, and Southern Asia.