What Makes A Biome?

What Makes A Biome?

Biomes are typically characterized by the resident biota within them. Currently, there is a disagreement in the scientific community about what exactly makes a biome.


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Biology, Ecology, Conservation, Earth Science


Deciduous Forest Fall

Trees in a deciduous forest during the fall.

Photograph by Clarita Berger/National Geographic Creative
Trees in a deciduous forest during the fall.
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The community of plants and animals that live in a certain climate is called a biome. The plants and animals of the Amazon rainforest are completely different from those in the Arctic tundra. But all scientists do not agree on what exactly constitutes a biome.

Biomes are sometimes confused with habitats and ecosystems. A habitat is specific to the area a population or species lives in, while ecosystems describe the way biota interact with an environment. This can include the way nutrients flow between plants and animals. Biomes can include many habitats and ecosystems because they describe life on a much larger scale.

Defining Biomes

Frederic E. Clements was an ecologist who studied the relationship between living things and their surroundings. He first used the term biome in 1916. Later, he worked with another ecologist, named Victor Shelford, to expand the definition of biome. By 1963, Shelford defined tundra, coniferous forest, deciduous forest, grassland, and desert as different biomes.

We can recognize and define biomes by the organisms that live there and by the climate of the area. The organisms within a biome have adapted for that particular environment. This makes it easier and safer for organisms to live in that environment. Climate is a major factor in determining types of plant and animal life that live in a particular biome. Several factors influence climate, such as latitude, geographic features, and how atmospheric conditions affect heat and moisture in that place.

Not all scientists agree about the number of defined biomes. Most agree that climate and the organisms that live there are important. The main types of biomes that come out of the different definitions are tundra, desert, grassland, coniferous forest, deciduous forest, tropical rainforest, and aquatic biomes.

Tundra Biomes

The tundra is located at the northernmost parts of the globe and is defined by long, cold winters and cool summers. The mammals that live in these areas have evolved to have thick fur and the ability to hibernate. This allows them to survive in the cold environment.

Desert Biomes

Deserts are defined by dryness, and can be located in both cold and warm climates. Life in these areas is adapted to a lack of water and nutrients.

Grassland Biomes

The grassland biome is found on every continent except Antarctica. It is flat and grassy, with very little tree cover. Large mammals that graze, such as elephants or bison, inhabit these areas, along with small mammals, birds, and predators.

Coniferous Forest Biomes

Coniferous forests are also known as taigas or boreal forests. These areas experience long, cold winters, short summers, and heavy precipitation, such as rain, sleet, or snow. The main types of vegetation are conifers and evergreen trees. Sometimes this category is split into another category known as the temperate forest, with temperatures that are not as cold. One example of this warmer forest is the western coast of North America, a humid forest system with redwoods and cedars.

Deciduous Forest Biomes

The deciduous forest biome is marked by broad-leafed trees, such as maple and oak. They lose their leaves seasonally as the temperatures begin to drop. These biomes are located in eastern North America, Western Europe, and northeastern Asia. These temperate regions have mild temperatures, but still have a distinct winter season.

Tropical Rainforest Biomes

Tropical rainforests in equatorial regions are warm and wet with a great variety of trees. The uppermost trees and branches in these forests form a kind of roof called a canopy. Leaf litter on the ground and the humid conditions create a layer of nutrients above the low-quality soil. This allows for biodiversity of plants, animals, and other organisms.

Aquatic Biomes

There are many ways to classify aquatic biomes. Often freshwater and saltwater biomes are defined separately based on water depth, temperature, and salinity. Terrestrial, or land, biomes are classified by vegetation types. But it's hard to define aquatic environments this way because they do not have much visible plant life.

Biomes are often thought of as separate regions, but they are not isolated from one another. Biomes do not typically have exact boundaries. There are transition zones between biomes, called ecotones. Some are natural while others are created by humans.

Many biome definitions exclude humans. However, some scientists believe that human presence is an important part in defining biomes. They think that most biomes are primarily influenced by humans. Scientists recognize that human activities, such as habitat destruction, will change how biomes are defined in the future.

Media Credits

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Tyson Brown, National Geographic Society
National Geographic Society
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Gina Borgia, National Geographic Society
Jeanna Sullivan, National Geographic Society
Program Specialists
Sarah Appleton, National Geographic Society, National Geographic Society
Margot Willis, National Geographic Society
Clint Parks
Roza Kavak
Last Updated

October 19, 2023

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