There are two tundra biomes. The first, the Arctic tundra, extends south from the North Pole down to the coniferous forests of the tiaga. Alpine tundra is a spread-out worldwide phenomena, and is located on mountains at extreme altitudes at which trees cannot grow.
While tundra biomes vary, there are a few typical tundra features. Beside extremely cold temperatures, the tundra has low biodiversity, relatively simple vegetation, little drainage, energy provided by dead organisms, short growth seasons and sweeping changes in population sizes based on the time of year.
The Arctic tundra is the world's youngest biome, as it was created only 10,000 years ago. The Arctic tundra covers approximately 20 percent of the earth's surface. The ground has a subsoil layer of ice called permafrost, which contains lots of gravel and fine materials.
Due to the extreme temperatures and sweeping seasonal changes, all tundra environments are very fragile. Both animals and plant life die due to seasonal changes. Development in tundra areas, particularly building based on oil speculation, has recently disrupted the life cycles of tundra organisms.
The tundra contains many forms of animal life, some of which are becoming increasingly at risk. These animals include arctic foxes, polar bears, caribou, ermines, grizzly bears, musk oxen and snowy owls.