<Tr> <Th> Area </Th> <Td> 11,563,300 km (4,464,600 sq mi) </Td> </Tr> <Tr> <Th> Climate type </Th> <Td> ET </Td> </Tr> <P> In physical geography, tundra (/ ˈtʌndrə, ˈtʊn - /) is a type of biome where the tree growth is hindered by low temperatures and short growing seasons . The term tundra comes through Russian тундра (tûndra) from the Kildin Sami word тӯндар (tūndâr) meaning "uplands", "treeless mountain tract". There are three types of tundra: Arctic tundra, alpine tundra, and Antarctic tundra . In tundra, the vegetation is composed of dwarf shrubs, sedges and grasses, mosses, and lichens . Scattered trees grow in some tundra regions . The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline . </P> <P> Arctic tundra occurs in the far Northern Hemisphere, north of the taiga belt . The word "tundra" usually refers only to the areas where the subsoil is permafrost, or permanently frozen soil . (It may also refer to the treeless plain in general, so that northern Sápmi would be included .) Permafrost tundra includes vast areas of northern Russia and Canada . The polar tundra is home to several peoples who are mostly nomadic reindeer herders, such as the Nganasan and Nenets in the permafrost area (and the Sami in Sápmi). </P>

Tundra ecosystem of the beer island in england