Doctora

Tundras are large, barren regions with no trees. In fact, the word tundra comes from the Finnish word tunturia, which means “treeless plain.” Tundras lie between the permanent ice of the far northand the northern forests of North America, Europe, and Asia. They cover about 20 percent of Earth's surface. They are some of the coldest places on Earth.

Features

Tundras may be flat, hilly, ormountainous. Little plant life grows on the bare or rocky ground. Tundras in coastal areas tend to be foggy. Snow covers the world's tundras for more than six months of the year.

Types of TundrasArctic tundras lie in northern Europe, Russia, Alaska, Canada, and Greenland. In these tundras the winter temperature may be as low as -25° F (-32° C). The summer temperature may rise only to 40° F(4° C). Because of these cold temperatures, Arctic tundras have a permanent layer of frozen soil, called permafrost. Some permafrost reaches as deep as 1,500 feet (456 meters).


Alpine tundraslie farther south than Arctic tundras. Alpine tundras are found in high mountains above the tree line. (The tree line is the highest place where trees can grow.) They have short, cool summers and lessextreme winters than Arctic tundras. Alpine tundras do not have a layer of permafrost.

Life in a Tundra

Only low-growing plants, such as mosses and shrubs, can survive in tundras. Plantlikeliving things called lichens also grow there.


Tundra animals must be able to survive long, cold winters. Many birds live there in the summer, but few stay through the winter. Some common tundraanimals are reindeer, Arctic foxes, snowy owls, musk oxen, and polar bears.


Very few people live in tundras. Arctic peoples, including the Eskimo (Inuit), tend to live in places where hunting andfishing can provide enough food year-round.

Resources

The ground of many tundras contains coal, oil, iron ore, lead, or other resources. Many companies have set up mining operations in tundra...