What Is the Meaning of Decomposition?

Earthworms help break down organic matter.

Decomposition is the process in which dead or decayed organic matter is converted into soil. Decomposers are organisms that facilitate this process, recycling organic matter into the soil. Without the process of decomposition, plants would quickly become starved of nutrients and wood and decaying animals would pile up on the forest floor.

Process

When a plant or animal dies decomposers eat at the decaying organic matter. This matter is broken down into smaller pieces in a process known as fragmentation. After larger decomposers such as maggots, beetles and earthworms begin the fragmentation process, bacteria and fungi complete the process. The end product of the process are small nutrient rich particles of soil called humus.

Identification

Decomposition takes place just about everywhere on the planet. If you leave a slice of bread on a countertop, it will become infested with mold in only a couple days. An animal carcass will have beetles and maggots eating the decaying flesh soon after death. Flies eating trash are another example of decomposition. Digging up a small pile of decaying leaves will show evidence of earthworms that are working on fragmentation.

Types

Decomposition takes two major forms: aerobic or anaerobic. Most processes of decomposition require aerobic (oxygen-rich) conditions, as larger organisms that start the fragmentation process require oxygen to live. Anaerobic conditions (oxygen-poor) are less than ideal, as only some forms of bacteria can live in oxygen-poor conditions. A landfill would be an example of anaerobic decomposition, while a forest floor would be an example of aerobic decomposition.

Time Frame

In nature, fragmentation by larger organisms is a fairly fast process. A dead animal will usually have its flesh stripped bare in days by predators, maggots and beetles. After the initial fragmentation process, it can take quite awhile to create humus. Even under the ideal situation of a compost pile, where organic materials are turned regularly and the ratio of carbon to nitrogen is controlled, full decomposition can take several months or longer.

Considerations

Every year landfills lock up large volumes of organic materials into concentrated areas. Landfills pack material using large compactor machines, a process that doesn't allow aerobic organisms to breathe. This results in very slow decomposition of organic matter, as only anaerobic orgasms can colonize the landfill in these conditions. Since landfills consume valuable natural resources that could otherwise be returned to the soil, individuals may want to practice their own decomposition by creating a compost pile.

References

• Offwell Woodland & Wildlife Trust: Decomposition
• Utah State University: Waste Not, Want Not: Fungi as Decomposers
• University of Illinois Extension: The Composting Process