Tundra

Tundra is a type of biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes directly from the Kildin Sami word tūndâr, meaning "uplands," "treeless mountain tract." Tundra vegetation is composed of dwarf shrubs, sedges and grasses, mosses, and lichens.

Characteristics

Tundra is the coldest of all the biomes. It is noted for its frost-molded landscapes, extremely low temperatures, little precipitation, poor nutrients, and short growing seasons. Dead organic material functions as a nutrient pool. The two major nutrients are nitrogen and phosphorus. Nitrogen is created by biological fixation, and phosphorus is created by precipitation.

Types of Tundra

Tundra is divided into three types:

1. 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.

2. Antarctic tundra occurs on Antarctica and on several Antarctic and subantarctic islands, including South Georgia and the South Sandwich Islands and the Kerguelen Islands. Most of Antarctica is too cold and dry to support vegetation, and most of the continent is covered by ice fields.

3. Alpine tundra does not contain trees because it is at high altitude. Alpine tundra transitions to subalpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone are known as Krummholz.

Climate

Tundra climates vary considerably. The most severe occur in the polar regions, where temperatures can fall to −60 °C (−76 °F). High winds often stir up snow, creating the illusion of continuous snowfall.

Flora and Fauna

Despite the harsh conditions, a variety of plants and animals have adapted to survive in the tundra. The flora includes low-growing plants, mosses, and lichens. Fauna includes animals such as reindeer, arctic foxes, and polar bears.

Human Interaction

Human activities, particularly those related to climate change, have significant impacts on the tundra. These include changes in biodiversity, melting permafrost, and shifts in vegetation patterns.

See Also

• Biome
• Permafrost
• Climate change

References

Tundra Resources
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