What is the Difference Between Detritus and Grazing Food Chain

The main difference between the detritus and grazing food chain is that the detritus food chain starts with the dead remains of organisms as a main source of energy, whereas the grazing food chain starts with the green plants as the main source of energy.

Detritus and grazing food chains are two types of food chains that occur in ecosystems. Generally, in ecosystems, there are different types of organisms that depend on various sources of food. In food chains, nutrients move through different trophic levels: producers at the bottom, followed by primary consumers, secondary consumers, and tertiary consumers.

Key Areas Covered

1. What is Detritus Food Chain
   • Definition, Characteristics, Importance
2. What is Grazing Food Chain
   • Definition, Characteristics, Importance
3. Similarities Between Detritus and Grazing Food Chain
   • Outline of Common Features
4. Difference Between Detritus and Grazing Food Chain
   • Comparison of Key Differences

Key Terms

Detritus Food Chain, Grazing Food Chain

What is Detritus Food Chain

Detritus food chain is a type of food chain that starts with dead organic matter. Generally, dead organic matter is decomposed by detritivores such as microorganisms. Detritivores or decomposers are the organisms that feed on dead organic matter. Later, predators eat detritivores. However, the most significant feature of the detritus food chain is that it releases energy and nutrients to the ecosystem.

Figure 1: Decomposers

For example, dead leaves are the dead organic matter that insect larvae eat. Usually, when the dead leaves are fallen into a shallow water body, the plant-eating phytophagous insects and their larvae, crabs, and copepods eat the dead leaves. Next, the carnivorous fishes eat insects. Moreover, large fishes eat these small fishes.

What is Grazing Food Chain

The grazing food chain is a type of food chain that starts with grazing primary consumers. The most significant feature of grazing food chains is their primary energy source, which is sunlight. In general, plants undergo photosynthesis by fixing the energy of sunlight. They produce simple organic compounds such as glucose. Then, primary consumers such as livestock can graze plants to obtain energy and nutrients from these photosynthetic plants.

Figure 2: Grazing Food Chain

For example, phytoplanktons are small microscopic organisms that undergo photosynthesis. Then, zooplanktons eat phytoplankton to obtain energy and nutrients. Small fish eat zooplankton and large fish eat small fish. Likewise, the energy from sunlight passes through the food chain. Overall, grazing food chains obtain energy and nutrients from the ecosystem.

Similarities Between Detritus and Grazing Food Chain

• Detritus and grazing food chains are two types of food chains that occur in ecosystems.
• Both food chains contain different trophic levels such as primary producer, primary consumer, secondary consumer, and tertiary consumer.
• Nutrients flow through each trophic level of the food chain.

Difference Between Detritus and Grazing Food Chain

Definition

Detritus food chain refers to a type of food chain that starts with dead organic matter while the grazing food chain refers to a type of food chain in which energy at the lowest trophic level is acquired via photosynthesis.

Primary Source of Energy

Dead and decaying organic matter serves as the primary source of energy in the detritus food chain while plants serve as the primary energy source in the grazing food chain.  

Size of the Food Chain

Usually, the detritus food chain is small while the grazing food chain is large.   

Type of Food Chain

Detritus food chain releases energy and nutrients to the ecosystem while grazing food chains fix energy and nutrients from the ecosystem.

Role of Food Chain

The Detritus food chain helps to fix inorganic nutrients while the grazing food chain adds energy to other trophic levels.

Examples

The detritus food chain contains soil bacteria, fungi, invertebrates, etc. as detritivores while the grazing food chain contains livestock as primary consumers.

Conclusion

In brief, the detritus food chain and grazing food chain are two types of food chains that occur in ecosystems. Detritus food chain contains detritivores as primary consumers while grazing food chains contain livestock as primary consumers. Detritus food chains release energy and nutrients into the ecosystem while grazing food chains obtain energy and nutrients from the ecosystem. Moreover, detritus food chains are smaller while grazing food chains are larger. However, the main difference between detritus and grazing food chains is their primary energy source and primary consumer.

References:

1. (2020, May 12). Detritus food chain: Definition, examples, faqs. BYJUS. Retrieved September 23, 2022.
2. (2022, August 4). Grazing food chain: Definition, types, examples, faqs. BYJUS. Retrieved September 23, 2022.

Image Courtesy:

1. “Decomposers” By BeaLeiderman – Own work (CC BY-NC-SA 2.0) via Flickr
2. “Seagrass trophic facilitations ” By Valdez, S.R. – Own Work (CC BY 4.0) via Commons Wikimedia