The Arctic tundra is a cold, vast, treeless area of low, swampy plains in the far north around the Arctic Ocean. It includes the northern lands of Europe (Lapland and Scandinavia), Asia (Siberia), and North America (Alaska and Canada), as well as most of Greenland. Another type of tundra is the alpine tundra, which is a biome that exists at the tops of high mountains.
Special features:
This is the earth's coldest biome. Since the sun does not rise for nearly six months of the year, it is not unusual for the temperature to be below -30°F in winter. The earth of the Arctic tundra has a permanently frozen subsoil, called permafrost, which makes it impossible for trees to grow. Frozen prehistoric animal remains have been found preserved in the permafrost.
In summer, a thin layer of topsoil thaws and creates many pools, lakes, and marshes, a haven for mosquitoes, midges, and blackflies. More than 100 species of migrant birds are attracted by the insect food and the safe feeding ground of the tundra. Other animals that live in this biome include polar bears, Arctic foxes, caribou, and grey wolves. Plants that you might find include small shrubs and cushion plants, and the lichen which cover the many rocks on the tundra's terrain. The Arctic is also famous for the beauty of its flowers during early autumn.
Coniferous ForestThe coniferous forest biome is south of the Arctic tundra. It stretches from Alaska straight across North America to the Atlantic Ocean and across Eurasia. The largest stretch of coniferous forest in the world, circling the earth in the Northern Hemisphere, is called the “taiga.” It supplies the bulk of the world's commercial softwood timber, which is used to make paper.
This biome is in the mild temperate zone of the Northern Hemisphere. Major regions are found in eastern North America, Europe, and eastern Asia.
A desert is an area where little or no life exists because of a lack of water. Scientists estimate that about one-fifth of the earth's land surface is desert. Deserts can be found on every continent except Europe. There are two different kinds: hot and dry (such as the Arabian and Sahara deserts) and cold and dry (such as Antarctica and the Gobi desert).
In North America, there are four major deserts: the Great Basin, the Mojave, the Sonoran, and the Chihuahuan. All but the Great Basin are hot deserts located in Mexico and the southwestern part of the United States. The Great Basin covers parts of Idaho, Nevada, Oregon, and Utah, and is considered a cold desert.
Grasslands are places with hot, dry climates that are perfect for growing food. They are known throughout the world by different names. In the U.S. they are called prairies and extend from the Midwest to the Rocky Mountains. In South Africa, grasslands are called the veld. Hot, tropical grasslands called <span>savannas </span>are found in South America and Africa. In Eurasia, temperate zone grasslands are called steppes; in South America, pampas.
Special features:
This inland biome is made of vast areas of grassy field. It receives so little rain that very few trees can grow. The U.S. prairies are used to graze cattle and to raise cereal crops. There is little variety of animal life. Some original prairie animals like the wolf and bison have come close to being eliminated from the habitat by hunters. Today, some of the most common grassland animals include the prairie dog and the mule deer in North America, the giraffe and the zebra in Africa, and the lion in Africa and Asia.
MountainsMountains exist on all the continents of the earth. Many of the world's mountains lie in two great belts. The Circum-Pacific chain, often called the Ring of Fire, runs from the west coast of the Americas through New Zealand and Australia and up through the Philippines to Japan. The other major belt, called the Alpine-Himalayan, or Tethyan, system, stretches from the Pyrenees in Spain and France through the Alps and on to the Himalayas before ending in Indonesia.
The animals of this biome have adapted to the cold, the lack of oxygen, and the rugged landscape. They include the mountain goat, ibex (wild goat), sheep, mountain lion, puma, and yak. All of them are excellent climbers, which means they can move freely in the steep, rocky landscape. Types of plants vary depending on geographic location and altitude. Lower elevations are commonly covered by forests, while very high elevations are usually treeless.
RainforestsTropical rainforests are found in Asia, Africa, South America, Central America, and on many of the Pacific islands. They are often found along the equator. Almost half of the world's tropical rainforests are in the South American country Brazil.
There are other types of rainforests around the world, too. For example, northern Australia has a “dry rainforest” that experiences a dry season each year, and the rainy Pacific Northwest in the United States has a “temperate rainforest” that is made up of evergreen trees.