Tundra
From Wikipedia, the free encyclopedia.

In physical geography, tundra is an area where tree growth is hindered by low temperatures and short growing seasons. The term tundra comes from the Finnish word tunturia, which means treeless plain.

There are two types of tundra: arctic tundra and alpine tundra. In both of these types, the dominant vegetation is grasses, mosses, and lichens. Trees do not grow in the tundra. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree-line or timberline.

See also:

• Fellfields
• Desert (tree growth hindered by low rainfall)
• Heath (tree growth hindered by human activity, not climate)

Arctic tundra

Arctic tundra occurs in the far Northern hemisphere, north of the taiga belt. Arctic tundra includes vast areas of northern Russia and Canada. The subsoil of arctic tundra is permafrost, which contains permanently frozen water. The arctic tundra is home to several peoples who are mostly nomadic reindeer herders, among them are the Saami.

Notable animals in the arctic tundra include:

• Caribou or Reindeer
• Musk ox
• Polar bear
• Lemmings

Due to the harsh climate of the arctic tundra, regions of this kind have seen little exploitation even though they are sometimes rich in natural resources such as oil and uranium. In recent time this has begun to change, and in Alaska, Russia and some other parts of the world the tundra is being ever more subjected to human interference.

Alpine tundra

Alpine tundra occurs at high enough altitude at any latitude on Earth. Alpine tundra is also lacking in trees, but does not usually have permafrost.

Notable animals in the alpine tundra include:

• Mountain goat
• Pika
• Marmot

External link

• Tundra biome information from the University of California
• Arctic tundra biome information from the WWF
• Alpine tundra information from the WWF

The original article can be found at: http://en.wikipedia.org/wiki/Tundra.
All text is available under the terms of the GNU Free Documentation License.