Education Menu
Describe the Probable Effects on an Ecosystem if All
Decomposers Were to Die
by Terri Schab, Demand Media
Decomposers, such as fungi, bacteria and invertebrates, play a
critical role in nutrient cycling and without them the earth's
ecosystem may not support life as we know it. Elements such as
carbon, nitrogen and phosphorus exist in limited amounts on
Earth, although huge amounts of carbon are being released into
the atmosphere from underground sources now by humans. It is
still extremely important that other nutrients be retained by the
process of re­use. Decomposers are organisms that are able to
chemically break down dead material and make these elements
available for use by other organisms. Without this breakdown of
dead material, dead bodies would pile up. So decomposers also
play a role in clean up also. Without them, life might not continue
as we know it and dead material would overwhelm the Earth.
Decomposers Recycle Carbon
Carbon in the atmosphere is taken up by plants and phytoplankton and
converted into proteins, carbohydrates and fats. Plants and phytoplankton
are then consumed by other organisms up the food chain. When these
organisms die, the carbon remains locked in their bodies. Decomposers are
Related Articles
able to break down this material and release carbon back into the
atmosphere and the cycle can begin again. Without decomposers, the carbon
would remain locked in dead organisms and could only be released through combustion. However, humans are having a
huge impact on the carbon cycle by the combustion of buried fossil fuels, which is increasing carbon in the atmosphere
rapidly. Still, without decomposers dead material would accumulate and other important nutrients would not be released.
An example of a decomposer in a forest ecosystem.
Decomposers Recycle Nitrogen
Nitrogen is needed by organisms to make proteins and nucleic acid. Our atmosphere has a lot of nitrogen, but it is not in a
form that can be used by organisms. Special bacteria and lightning can change the nitrogen into a form that can be used.
This nitrogen can be used by plants, the foundation of the food chain. When organisms die, decomposers break down the
dead bodies and the nitrogen is released and another type of bacteria breaks it down into gaseous nitrogen. Without
decomposers and other types of bacteria, the nitrogen cycle would not be maintained. In all likelihood, plants would die
off and the food chain would dissolve.
Decomposers Recycle Phosphorous
Phosphorous is an essential nutrient for organisms. It is contained in rocks and minerals and is weathered down and
taken up by plants in its original form. Again, those plants are eaten. When the plants and other organisms die,
phosphorous is contained in the bodies in a form which cannot be used by plants. Bacterial decomposers convert the
phosphorous back into its original form so it can be used again. Without decomposers, this essential nutrient would not
allow for plant life to continue. Again, all other forms of life would be negatively affected.
Decomposers are Essential for Life
If all decomposers were to die off, these nutrient cycles would be severely disrupted and the essential elements, perhaps
with the exception of carbon, would not be available for life to continue. Nitrogen and phosphorus would be locked in
dead material. In all probability, life as we know it would not continue and there would be a huge build up of dead
material with many compounds locked inside these bodies.
References
University of the Western Cape: Dept. of Biodiversity and Conservation Biology: Nutrient
cycling(http://webcache.googleusercontent.com/search?
q=cache:Kcpu2AtmSSQJ:www.bcb.uwc.ac.za/sci_ed/grade10/ecology/cycling/nutr.htm+&cd=1&hl=en&ct=clnk&gl=us)
Society for General Microbiology: Nitrogen Cycle(http://www.microbiologyonline.org.uk/aboutmicrobiology/microbes-and-the-outdoors/nitrogen-cycle)
Elmhurst College: Phosphorus Cycle(https://www.google.com/#q=phosphorus+cycle&undefined=undefined)
Resources
Northwestern University: What is a
decomposer(http://www.qrg.northwestern.edu/projects/marssim/simhtml/info/whats-a-decomposer.html)
NatureWorks: Decomposers(http://www.nhptv.org/natureworks/nwep11b.htm)
Environmental Biogeochemistry Laboratory: Ecosystem Nutrient
Cycling(http://moab.colorado.edu/EcosystemNutrientCycling.html)
About the Author
Terri Schab is an biologist/wetland scientist who is passionate about ecosystem biogeochemical functions, environmental
policy and any plant or fungi that exists. She was the lead scientist for a large wetland migration bank in the Pacific
Northwest and is especially passionate about chemistry, ecosystem functions, green issues and science in general. She has
also studied mathematics and has taught statistics in her career.
Photo Credits
David De Lossy/Photodisc/Getty Images