Nature · Earth Science
Earth’s great communities of life
A biome is a large region defined by its climate and the community of plants and animals adapted to it. From steaming rainforests to frozen tundra, biomes are the broad brushstrokes of the living planet — shaped chiefly by temperature and rainfall, and repeating in similar forms wherever those conditions recur.
Latitude, altitude, ocean currents and mountains set the pattern of temperature and rainfall across the globe. Where those patterns match, similar biomes appear — belts of rainforest near the equator, deserts around the tropics, grasslands and forests in the temperate zones, and tundra near the poles.
Climate zones stack from the hot, wet equator to the cold poles — and up a mountainside in miniature.
Hot, wet and teeming with life
Straddling the equator, rainforests are warm and drenched year-round, packing more species into their layered canopies than any other land biome on Earth.
The realm of scarcity
Deserts receive so little rain that life must hoard every drop. Around the tropics, sinking dry air creates great belts of desert where only the toughest specialists survive.
Seas of grass
Where rainfall is too low for forest but too high for desert, grasses rule. Tropical savannas and temperate prairies feed the planet’s great herds of grazing animals.
The forests of the cooler world
Cooler, seasonal climates grow broadleaf temperate forests that blaze and drop their leaves each autumn, and the vast evergreen boreal forest — the taiga — that rings the far north.