The world's biomes.

A biome is a large region where a distinct variety of plants and animals live together, Each biome has its own particular climate, or the average weather in an area. This poster shows some of the world's major land biomes. Explore the color-coded map, and to learn what makes these biomes so unique.

Temperate Forest This biome has four seasons: winter, spring, summer, and fall. By winter, the biome's deciduous trees have shed their leaves, which grow back in the spring. In the fall, the leaves' green pigment, or chlorophyll, breaks down to reveal reds and yellows. Many birds and mammals live here.

Grasslands

These open, flat areas are covered with grasses and few trees. Tropical grasslands, called savannas, are warm all year, with a wet and a dry season. Zebras, elephants, and rhinos roam the savannas. Temperate grasslands, like the Great Plains, have hot summers and cold winters.

Tundra In this biome, temperatures can dip below freezing (0[degrees]C, or 32[degrees]F) for 10 months a year. It's so cold that a layer of earth below the soil stays frozen all year. This permafrost keeps out deep-rooted trees. Most residents use the tundra as a summer home. An unusual year-round dweller: the polar bear.

Desert This biome receives less than 25 cm (10 in.) of precipitation a year. Hot deserts, like those in Australia, stay toasty all year, while cold deserts, such as Mongolia's Gobi desert, can be chilly. To survive, reptiles and mammals, such as the red kangaroo, have adapted to little water and intense sunshine.

Tropical Rain Forest Found near Earth's equator (imaginary line around Earth's middle), this biome gets lots of sunshine and more than 2.5 meters (8 feet) of rain a year. This warm biome supports the world's greatest diversity of plants and animals, including frogs, monkeys, and birds.

Boreal Forest This belt of coniferous, or cone-bearing, trees stretches across northern Asia, Europe, and North America, Winters are long and snowy, while summers are short and cool. Many birds, such as the common redpoll, migrate north to breed in the boreal forest during its brief summer.