Tundra

In physical geography, tundra is the part of the world in which the tree growth is hindered by low temperatures and short growing seasons. The word comes from the Sami tūndâr, which means "uplands," "tundra," or "treeless mountains."

There are three types of tundra: Arctic tundra, Antarctic tundra, and alpine tundra. In all three types, the plants are mostly grass, moss, and lichens. Trees grow in some of the tundra. The boundary between the tundra and the forest is known as the tree line or timberline. The area itself encircles the Arctic Ocean of the Northern Hemisphere. The climate in a tundra biome consists of freezing cold and dryness in the winter and cold summers. The tundra ground is a barren place and is often covered with rocks.

Most water on the tundra is permafrost  permanent frozen soil. Permafrost and fierce winds prevent large trees from growing deep roots. Plants in the tundra are small and grow near the ground. Plants, called "cushions," grow in tight clumps in the tundra, but lichens are the dominant plants and cover the rocks. The few trees that do grow on the tundra are dwarf willows and birch.

The deep and cold snow makes life in the tundra very difficult. Animal must adapt to survive. Some have thick fur that turns white during the winter. Others find places to hibernate during the winter months. Some examples of animals that live in the tundra are rodents, hares, sables, caribou, wolves, arctic foxes, bears, walruses, seals, and snowy owls.Chernov Y.I. 1998. The living tundra: studies in polar research. Cambridge University Press. 

 References 

 Other websites 

WWF Tundra Ecoregions 
The Arctic biome at Classroom of the Future
British Antarctica Survey
Antarctica: West of the Transantarctic Mountains
Tundra Food Chain | How The Tundra Food Chain Works? 

Category:Biomes