A biome is an area of the planet that can be classified according to the plants and animals that live in it. Temperature, soil, and the amount of light and water help determine what life exists in a biome.
A biome is different from an ecosystem. An ecosystem is the interaction of living and nonliving things in an environment. A biome is a specific geographic area notable for the species living there. A biome can be made up of many ecosystems. For example, an aquatic biome can contain ecosystems such as coral reefs and kelp forests.
Not all scientists classify biomes in the same way. Some use broad classifications and count as few as six biomes. These are forest, grassland, freshwater, marine, desert, and tundra.
Other scientists use more precise classifications and list dozens of different biomes. For example, they consider different kinds of forests to be different biomes. Tropical rain forests that are warm and wet year-round are one biome. Temperate deciduous forests—those that have cold winters, warm summers, and are dominated by trees that lose their leaves—are a different biome. Taiga forests, which are in cold regions and are dominated by cone-bearing firs and spruces, are yet another biome.
Boundaries between biomes are not always sharply defined. For instance, there are sometimes transition zones between grassland and forest biomes. Coasts and wetlands are transition zones between terrestrial and aquatic biomes.
Biomes move as the climate changes. Ten thousand years ago, parts of North Africa were lush landscapes cut by flowing rivers. Hippopotamuses, giraffes, and crocodiles lived amid abundant trees. Gradually, the climate dried out. Today, this region is part of the Sahara Desert, the world's largest desert.
There are more than a dozen ways to classify biomes. Climatologists, botanists, ecologists, biologists, and anthropologists have different criteria for deciding what constitutes a biome. One of the simplest classification systems has only two biomes: terrestrial (land) and aquatic (water). One of the most complex has more than a dozen.
Term Part of Speech Definition Encyclopedic Entry abundant Adjective
in large amounts.
in the middle of.
having to do with water.
area of the planet which can be classified according to the plant and animal life in it.
Encyclopedic Entry: biome broad Adjective
wide or expansive.
to identify or arrange by specific type or characteristic.
all weather conditions for a given location over a period of time.
Encyclopedic Entry: climate coast Noun
edge of land along the sea or other large body of water.
Encyclopedic Entry: coast coral reef Noun
rocky ocean features made up of millions of coral skeletons.
type of plant that sheds its leaves once a year.
area of land that receives no more than 25 centimeters (10 inches) of precipitation a year.
Encyclopedic Entry: desert ecosystem Noun
community and interactions of living and nonliving things in an area.
Encyclopedic Entry: ecosystem environment Noun
conditions that surround and influence an organism or community.
variety of pine tree.
ecosystem filled with trees and underbrush.
water that is not salty.
ecosystem with large, flat areas of grasses.
kelp forest Noun
underwater habitat filled with tall seaweeds known as kelp.
abundant and rich.
having to do with the ocean.
series of links along which movement or communication can take place.
rain forest Noun
area of tall, mostly evergreen trees and a high amount of rainfall.
Encyclopedic Entry: Rain forest Sahara Desert Noun
world's largest desert, in north Africa.
top layer of the Earth's surface where plants can grow.
coniferous, or cone-bearing, tree.
evergreen forest in cool, northern latitudes. Also called boreal forest.
Encyclopedic Entry: taiga temperature Noun
degree of hotness or coldness measured by a thermometer with a numerical scale.
Encyclopedic Entry: temperature terrestrial Adjective
having to do with the Earth or dry land.
transition zone Noun
area between two natural or artificial regions.
existing in the tropics, the latitudes between the Tropic of Cancer in the north and the Tropic of Capricorn in the south.
cold, treeless region in Arctic and Antarctic climates.
area of land covered by shallow water or saturated by water.
Encyclopedic Entry: wetland