Resource Library

ENCYCLOPEDIC ENTRY
ENCYCLOPEDIC ENTRY

Decomposers

Decomposers

Decomposers play a critical role in the flow of energy through an ecosystem. They break apart dead organisms into simpler inorganic materials, making nutrients available to primary producers.

Grades

5 - 8

Subjects

Biology, Conservation, Ecology

Image

Millipede Detritivore

While decomposers break down dead, organic materials, detritivores—like millipedes, earthworms, and termites—eat dead organisms and wastes.

Photograph by Ankit Shrimp/EyeEm

When you have an empty bottle, do you recycle it so the plastic or glass can be used again? Nature has its own recycling system: a group of organisms called decomposers.

Decomposers feed on dead things: dead plant materials such as leaf litter and wood, animal carcasses, and feces. They perform a valuable service as Earth’s cleanup crew. Without decomposers, dead leaves, dead insects, and dead animals would pile up everywhere. Imagine what the world would look like!

More importantly, decomposers make vital nutrients available to an ecosystem’s primary producers—usually plants and algae. Decomposers break apart complex organic materials into more elementary substances: water and carbon dioxide, plus simple compounds containing nitrogen, phosphorus, and calcium. All of these components are substances that plants need to grow.

Some decomposers are specialized and break down only a certain kind of dead organism. Others are generalists that feed on lots of different materials. Thanks to decomposers, nutrients get added back to the soil or water, so the producers can use them to grow and reproduce.

Most decomposers are microscopic organisms, including protozoa and bacteria. Other decomposers are big enough to see without a microscope. They include fungi along with invertebrate organisms sometimes called detritivores, which include earthworms, termites, and millipedes.

Fungi are important decomposers, especially in forests. Some kinds of fungi, such as mushrooms, look like plants. But fungi do not contain chlorophyll, the pigment that green plants use to make their own food with the energy of sunlight. Instead, fungi get all their nutrients from dead materials that they break down with special enzymes.

The next time you see a forest floor carpeted with dead leaves or a dead bird lying under a bush, take a moment to appreciate decomposers for the way they keep nutrients flowing through an ecosystem.

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Director
Tyson Brown, National Geographic Society
Author
National Geographic Society
Production Managers
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
Producer
Clint Parks
other
Last Updated

May 20, 2022

For information on user permissions, please read our Terms of Service. If you have questions about licensing content on this page, please contact ngimagecollection@natgeo.com for more information and to obtain a license. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. She or he will best know the preferred format. When you reach out to him or her, you will need the page title, URL, and the date you accessed the resource.

Media

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text

Text on this page is printable and can be used according to our Terms of Service.

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources