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Tundra means a “barren land” since they are found where environmental conditions are very severe. There are two types of tundra- arctic and alpine.
♤ Distribution: Arctic tundra extends as a continuous belt below the polar ice cap and above the tree line in the northern hemisphere. It occupies the northern fringe of Canada, Alaska, European Russia, Siberia and island group of Arctic Ocean. On the south pole, tundra is very small since most of it is covered by ocean .
Alpine tundra occurs at high mountains above the with respect to Arctic mountains are found at all latitudes therefore alpine tundra shows day and night temperature variations.
♤ Flora and fauna: Typical vegetation of arctic tundra is cotton grass, sedges, dwarf heath, willows, birches and lichens. Animals of tundra are reindeer, musk ox, arctic hare, caribous, lemmings and squirrel.
Most of them have long life e.g. arctic willow has a life span of 150 to 300 years. They are protected from chillness by the presence of thick cuticle and epidermal hair. Mammals of the tundra region have large body size, small tail and small ear to avoid the loss of heat from the surface. The body is covered with fur for insulation.
Insects have short life cycles which are completed during favourable period of the year.