The Arctic Tundra is the world's youngest biome; it was formed 10,000 years ago.
Tundra comes from the Finnish tunturi, which means treeless plain. The Arctic tundra covers about 20 percent of the Earth's surface. Few species can survive in the arctic conditions, in which average annual winter temperatures are minus-70 Fahrenheit. Even the summer growing season lasts only 50 to 60 days and features temperatures of 37-54 Fahrenheit.
Plants
Tundra plants tend to grow low to the ground, where they are somewhat shielded from arctic winds that blow up to 100 miles per hour. About 400 variety of flowers grow on the tundra during the short summer season. Willows, sedges and grasses are common, many grow in dwarf form compared to their southern cousins. Lichens and mosses are very common and are a steady supply of food for many tundra animals.
Insects
Despite the cold conditions, insects are plentiful on the tundra. Black flies and mosquitoes rise in clouds in springtime. Tundra mammals such as caribou are prone to being swarmed by female mosquitoes seeking nutrients before laying eggs. Humans on the tundra are another favorite target. Springtails, weevils, beetles, spiders and blow flies are also plentiful. Many insects living on the tundra have dark bodies to help them absorb sunlight, and they have developed a form of antifreeze in their blood.
Birds
Where there are insects in large numbers there will be birds. The Arctic tern flies 22,000 miles from the Antarctic to the Arctic to nest and raise its young. At the end of the arctic summer in August, it returns to the Antarctic. Snow geese who spend the winter in Mexico, Tundra swans who winter in the United States, nest in the tundra and feast on insects. Ravens, snowy owls and ptarmigans have adapted to live in the region year-round.
Mammals
During the warmer months, large herds of caribou migrate hundreds of miles from the coniferous forests south of the tundra to graze on the grasses, lichen and mosses that grow in the warmer months. Mammals that live on the tundra year-round rarely hibernate because the spring and summer seasons are not long enough for them to acquire the required body fat. The Arctic hare and the Arctic fox are among these along with musk ox, lemmings and the tundra's most famous resident the polar bear.
Tags: miles from, warmer months