What Are Tundras?
The Arctic tundra is a plain that is predominantly treeless and has a layer of soil under the subsoil that remains frozen year round called the permafrost. Although some tundra areas have scrubby trees and vegetation near streams, the trees are generally stunted and do not grow large. In fact, the word "tundra" was derived from "tunturia," the Finnish word for "treeless land."
Types of Tundra
Although most people assume that tundra is only found in the Arctic Circle, there are actually 2 kinds of tundra. The Arctic tundra is found near the North Pole while the Alpine tundra is found above the tree line of tall mountains.
Summer in Arctic Tundras
The summer in the Arctic tundra is short, lasting anywhere from 6 to 10 weeks. The topsoil thaws, allowing small plants to grow and bloom. Because the soil is permanently frozen beneath the topsoil, melting snow and ice cannot drain into the soil, causing bogs and ponds during this brief period of warmth. Arctic tundras receive sunlight for nearly 24 hours a day during this period. Plants grow rapidly in the added sun.
Plants
Plants of the tundra include lichen and cushion plant, a small plant that grows close to the ground. Grasses and small flowers also grow in the tundra. In some areas, small shrubs, willow and birch trees also grow. Alpine plants are small and cling to the sides of rocks. Waxy tough leaves protect the plants from the damaging effects of high winds and low temperatures.
Animals
Animals in the Arctic tundra are well adapted to the cold climate and lack of rainfall. These include the Arctic fox, caribou, polar bear and the Arctic hare. Some animals, like the caribou, migrate to warmer temperatures during the coldest season and return as the land warms. Others like the Arctic ground squirrel hibernate through the coldest parts of winter. Few reptiles or amphibians are able to withstand the harsh winter weather of the tundra. Even in these cold temperatures, mosquitoes and black flies are able to breed and survive during the warm season.
Temperatures
Temperatures in the Arctic tundra average --30 degrees F during the winter months and range from 37 to 54 degrees F in the summer. Snow and rainfall amounts generally range between 6 and 10 inches a year. Alpine tundras range in temperature but generally remain below freezing for all but 2 or 3 months in the summer. High winds cause wind chills far below the actual temperature. Many areas remain snow covered throughout the year with small plants emerging in windswept crevices between rocks.
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