Biologists are not unanimous in how they classify biomes or in the number of biomes.
Biomes represent a superficial and somewhat arbitrary classification of ecosystems.
Collectively, biomes comprise the biosphere, which is the thin area of the earth's surface where all organisms live.
One biologist may classify one particular area as one biome, while another classifies the same region as an ecotone (the area where one biome overlaps another) or as a different biome.
Using the Koppen Classification system, terrestrial biomes are listed such as Tropical Rainforest (Af), Tropical Rainforest, evergreen forest (Am), Savannah (Aw), Desert (BW), Polar (E), and so forth.
World terrestrial biomes are controlled by climate, and in particular by air temperature and precipitation.
Others add such biomes as temperate rain forests, chaparral, and coniferous forests, and further delineate aquatic biomes into ocean, estuaries, and so forth.
The subcategories of the Marine Biome (Ocean, Intertidal Zones, and Estuaries) are also considered biomes.
Biomes are a dynamic, rather than static, entity, and have changed throughout geological history.
Among commonly recognized land biomes are tundra, taiga, temperate deciduous forest, grasslands, deserts, and tropical rain forests, and two major water biomes are those of marine and fresh water.
Classification of biomes varies and no one system dominates biogeographical studies.
Biomes are most strongly defined by global distributions of vegetation types, which are influenced by global climate, soils, and other physical environment factors.
LOCATION: The tundra biome is the coldest of all biomes. It is also quite big. The tundra covers about one fifth of the land on earth. The word tundra comes from a Finnish word that means treeless plain, which is a good description of the biome.