tundra

tundra , treeless plains of N North America and N Eurasia, lying principally along the Arctic Circle, on the coasts and islands of the Arctic Ocean, and to the north of the coniferous forest belt. The tundra area is widest in N Siberia on the Kara Sea and reaches as far south as 60° N at the neck of the Kamchatka peninsula. Although sometimes called the Arctic steppe and situated mainly within the Arctic Circle, it reaches southward into the Scandinavian, Timan, and Ural mts. For most of the year the mean monthly temperature is below the freezing point; winters are long and severe. The summers are short and relatively warm, but even in July the mean monthly temperature does not rise above 50°F (10°C). Although high temperatures may be reached during a summer day, the subsoil is perpetually frozen. During summer, sedges, mosses, and lichens appear in abundance, along with some flowering plants. Among the few large animal species found in the tundra are the caribou, the arctic fox, the snowshoe rabbit, and occasionally the polar bear. Precipitation is spread evenly during the year and is slight, varying from 8 to 12 in. (20-30 cm). Evaporation is low, and much of the flat ground in areas of poor drainage becomes swampy during the summer months. Because there are very few species of flora and fauna, the destruction of the tundra is a simple process. The elimination of a single species or the disruption of the permanently frozen subsoil (permafrost) may severely damage this fragile ecosystem. Russia's tundra supports a small human population mostly consisting of the Nensty (Samoyedes) and the Komi. Eskimos inhabit the North American tundra.

Bibliography: See E. Bowen, Grasslands and Tundra (1985).

tundra vast level treeless region of Russia. XIX. — Russ. túndra, of Lappish orig.

tundra Treeless, level, or gently undulating plain characteristic of arctic and subarctic regions. It is marshy with dark soil that supports mosses, lichens, and low shrubs. It has a permanently frozen subsoil known as permafrost.