Definition: A distinct group lifeforms and the environment in which they are found.
The world's biomes can be grouped into the following types:
- Aquatic: The aquatic biome includes freshwater habitats (ponds, lakes, streams, wetlands) as well as marine habitats (ocean, coastal waters, estuaries, coral reefs).
- Desert: The desert biome includes areas where rainfall is less than 50 cm/year. Desert habitat types include hot and dry, semiarid, coastal, and cold.
- Forest: The forest biome includes areas that are dominated by trees and other woody vegetation.
- Grassland: The grassland biome includes habitats dominated by grasses (not trees and shrubs). Grasslands include tropical savannas and temperate grasslands (prairies).
- Tundra: The tundra biome includes cold habitats with low biotic diversity and simple vegetation structure. The tundra biome includes arctic tundra and alpin tundra habitats.
Source: Pullen, S. Ed. and The UC Berkeley Biomes Group. 'The World's Biomes', (On-line). UC Berkely Museum of Paleontology

