The five types of biomes -- regions of the planet that have similar climate, plants and animals -- are aquatic, desert, forest, grassland and tundra. Some authorities divide these into subcategories.
The aquatic biome is underwater. It consists of freshwater regions and marine or saltwater regions. The three types of freshwater regions are ponds and lakes, streams and rivers, and wetlands. Marine regions include oceans, coral reefs and estuaries.
Deserts are areas with very little rainfall or standing water, so that they are very dry. Although many deserts have a hot climate because they are near the equator, cold deserts also exist and may get a lot of snow. Four subcategories of the desert biome are hot and dry, arid, coastal and cold. Plant life is sparse or nonexistent in deserts, and desert animals are usually reptiles and small mammals.
Forests are areas made up of trees and other woody plants. They can be tropical, temperate or boreal forests, called taiga. Tropical forests are home to the most diverse range of plants and animals. They have rainy and dry seasons but no winters. Temperate forests have all four seasons. Taiga is the largest land biome, located in northern latitudes. Its climate is cold and snowy.
Grasslands are made up of grasses rather than trees. Savannas occur in hot or warm climates where rain falls only at certain times during the year. These grasslands have sparsely placed individual trees. Temperate grasslands have no trees or shrubs; they include prairies, with tall grasses, and steppes, with short grasses
Tundra is the coldest biome, consisting of treeless plains, carnivorous animals and migratory birds. In arctic tundra, plants are short and grow in groups to withstand the cold and the winds. Alpine tundra regions are in the mountains at altitudes higher than tree level.