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Decomposers are the organisms that have the ability to decay or break down the dead organisms. Decomposers are also defined as those organism that have the ability of decomposition.
What is a Decomposer?
The decomposers break down dead material of both animals and plants in the ecosystem. Decomposition is the process of breaking down the complex organic matter into simpler substances.
The examples of decomposers are bacteria and fungi. These organisms feed upon the dead organic material and convert the matter into simpler substances. They break down the nutrient matter of the ecosystem and play an important role in the food chain. This decomposed organic matter is recycled and absorbed by plants and other primary producers.
In ecological pyramid, they found in lowest position. Decomposers are heterotrophic organisms and get nutrients from the dead organic material.
Decomposers are mainly saprophytic in nature. The word saprophyte is made up of two words, sapro meaning “rotten material” and phyte meaning “plant”. Saprophytes are those organisms which feed upon the dead plant material or plant litter. The break the plant litter into molecular elements like carbon, calcium, and nitrogen etc. They convert the organic dead mass into simpler substances with some digestive enzymes.
For example, proteins are broken down into amino acids and carbohydrates are converted into simple sugars like glucose and fructose. They can survive in high humid conditions, and in presence of oxygen. Some common features of saprophytes include-
• Have filaments
• Heterotrophic in nature
• Reproduce by means of spores
Importance of Decomposer
There are various crucial functions carried out by the decomposers. In ecosystem, they have some major functions like decomposition or disintegration of the dead organisms.
Ecological Cleansers and Balance Providers: Decomposers play an important role in cleansing the environment by decomposing the dead material and also help to create a biosphere for the new life. Thus they have an important role as ecological cleansers and also in balancing the ecosystem.
Recycling of Nutrients: Decomposers convert the dead material into molecular elements like carbon, nitrogen, phosphorus, etc. These elements are then absorbed by the primary producers like plants, algae etc., thus, decomposers helps in recycling the nutrients. The essential elements for the survival of producers are provided by decomposers.
Types of Decomposer
The decomposers are categorized into four types, namely fungi, insects, earthworms, and bacteria.
Fungi are heterotrophic organisms that do not perform photosynthesis and feed on other organisms. Several fungi are saprophytic that feed upon dead material and principal decomposers in the ecosystem. Fungi secrete some enzymes in the environment to break down the plant litter into simpler molecules. These enzymes digest the material, which is absorbed by the fungi itself and thus, it get nutrient from the litter. Fungi grow in high humid conditions.
Several insects like flies, maggots, dung beetles, and ants also help in decomposition. These insects are categorized as detritivores because they digest the dead material in their intestinal tract. Based upon the type of organic matter, the decomposers (insects) are classified into different categories-
• Dead plant tissue feeding insects
• Dead animal tissue feeding insects
Earthworms are also considered as detritivores that orally feed upon the dead material. They are also known as friendly worms because of their ability to enrich soil by decomposition of litter. They release nutrients like phosphorus and calcium in the soil and helps to improve soil quality.
Bacteria are microscopic, prokaryotic organisms that are ubiquitous in nature. They also involved in the process of decomposition. Bacteria also decompose the litter into carbon, nitrogen, etc. and helps in recycling of these nutrients. These nutrients are then absorbed by the producers of the food chain.
Decomposers and Detritivores
A group of organisms that break down the dead organic material into simpler molecules are called decomposers. The decomposers are categorized into two major groups: Detritivores and saprotrophs.
Detritivores are the type of decomposers including some animals like, worms and insects, whereas saprotrophs include fungi and bacteria. Sometimes, decomposers and detritivores are used as synonyms.
|A group of organisms that decay the dead material.||A class of decomposers that feed orally in the dead material.|
|They act by secreting some digestive enzymes.||Act by digesting the matter in their digestive tract.|
|Cannot digest the large clumps of dead organic matter.||They can digest upon large clumps.|
|Examples- Fungi, bacteria, earthworms||Examples- Earthworms, insects|
Decomposer vs Scavengers
Scavengers are the organisms that initiates the process of decomposition. There are some differences between Scavengers and decomposers-
|The process of decomposition has initiated by scavengers.||They act on the particles that are decomposed by scavengers.|
|Act as initiators||Act as finishers|
|Example- Vultures, Flies||Examples- Fungi, Bacteria, earthworms|
Decomposition is the process of breaking down the dead organic material into simpler molecules. The process completed by some organisms called decomposers. Some common decomposers are fungi, bacteria.
Stages of Decomposition
The process of decomposition completes in five stages:
The organic material is fragmented in this stage. The process initiates by detritivores to increase the surface area for decomposers. The detritivores feed upon the dead material and digest it with their digestive tract. Detritivores converts the matter into fragments for decomposers to act upon.
The fragmentation is followed by Leaching. In this stage, the water soluble nutrients present in the fragmented detritus are percolates through the soil.
Third stage include secretion of enzymes by decomposers. These enzymes catabolize the decomposition process and convert the organic material into simpler substances.
The formation of humus by dead matter is called humification. The amorphous substances form humus, which is very fertile.
It is the last step of decomposition. In this step the minerals are released in soil. The minerals or organic substances includes calcium, potassium, carbon, nitrogen etc.
Factors Affecting Decomposition
• Quality of Litter: Decomposition is affected by the structural and chemical properties of the litter.
• Temperature: The decomposition slower down with low temperature. Low temperature also decrease the microbial growth.
• Aeration: Aeration is essential factor for decomposition, thus oxygen is very important.
• Inorganic Chemicals: The process of decomposition decreases with presence of inorganic minerals.
• Moisture: moisture is essential factor that increases the rate of decomposition.
i. Decomposers in Aquatic Ecosystem
1. Oceans / Seawater Decomposers: They are found in oceans and in seawater.
Some common examples are:
• Christmas tree worms
• Hagfish are the scavengers
• Sea urchin
• Tube worm
2. Freshwater Decomposers: Mostly found in fresh water bodies like rivers, ponds, etc.
• Trumpet snail
• Water mold
ii. Terrestrial Ecosystem Decomposers
1. Forest Ecosystem Decomposers: Beetle, Earthworms, Millipede, Mushroom, Slime mold, Slug, etc.
2. Desert Ecosystem Decomposers: Dung beetle, Fly, Millipede, Saharan silver ant
3. Grassland Ecosystem Decomposers: Acidio bacteria, Termite
4. Mountain Ecosystem Decomposers: Mountain pine bark beetle, Purple fairy fingers
- Role of phyllosphere fungi of forest trees in the development of decomposer fungal communities and decomposition processes of leaf litter. Can J Microbiol . 2006 Aug;52(8):701-16.
- Methods for assessing the impact of avermectins on the decomposer community of sheep pastures. Vet Parasitol . 1993 Jun;48(1-4):87-97.
- Stoichiometric imbalances between terrestrial decomposer communities and their resources: mechanisms and implications of microbial adaptations to their resources. Front Microbiol . 2014 Feb 3;5:22.
- Thermal adaptation of decomposer communities in warming soils. Front Microbiol . 2013 Nov 12;4:333.
- Current trends in forensic odontology. J Forensic Dent Sci . Sep-Dec 2017;9(3):115-119.