Difference Between Detrital and Grazing Food Chain

The key difference between detrital and grazing food chain is that detrital food chain is a food chain that begins with dead organic matter as the main source of energy while grazing food chain is a food chain that begins with green plants as the main source of energy.

A food chain illustrates the feeding relationships between species in a biotic community. There are two main types of food chains as grazing food chain and detrital food chain. Grazing food chains are based on photosynthetic plants. Therefore, green plants are the main source of energy in grazing food chains. Detrital food chains are based on decomposers or detritivores. Hence, the dead remains of organisms are the main source of energy in detrital food chains.

CONTENTS

1. Overview and Key Difference
2. What is a Detrital Food Chain
3. What is a Grazing Food Chain
4. Similarities Between Detrital and Grazing Food Chain
5. Side by Side Comparison – Detrital vs Grazing Food Chain in Tabular Form
6. Summary

What is a Detrital Food Chain?

Decomposers or detritivores are organisms that feed on decaying organic matter (dead organisms). A food chain that is based on detritivores is called a detrital food chain. Decomposers are mainly microorganisms, such as bacteria and fungi. Hence, the detrital food chain mostly consists of microorganisms.

They decompose dead organic matter in the ground and participate in recycling organic matter in the environment. Detrital food chains are small compared to grazing food chains.

What is a Grazing Food Chain?

A grazing food chain is a food chain that begins with a producer or a photosynthetic plant. Therefore, grazing food chains are based on green plants. The first trophic level is a producer in the grazing food chain. The next level is a herbivore, and other levels can be occupied by an omnivore or carnivore.

Generally, grazing food chains are larger. These food chains release energy to the environment. Energy is released from plants to plant-eating animals and then into other animals. An example of a grazing food chain is shown below.

Grass ⇒ Rabbit ⇒ Wolf ⇒ Tiger

What are the Similarities Between Detrital and Grazing Food Chain?

• Detrital and grazing food chains are two types of food chains.
• There are at least three trophic levels in a food chain.

What is the Difference Between Detrital and Grazing Food Chain?

A food chain that starts with dead organic matter is known as a detrital food chain. A food chain that begins with a green plant is called a grazing food chain. So, this is the key difference between detrital and grazing food chain. Decomposers are the first trophic level of a detrital food chain, while a green plant is the first trophic level of a grazing food chain. Generally, a grazing food chain is larger than a detrital food chain. Moreover, a detrital food chain mostly consists of microorganisms. But in contrast, a grazing food chain consists of macroscopic organisms. Thus, this is another difference between detrital and grazing food chain.

The below infographic shows more differences between detrital and grazing food chain in tabular form.

Summary – Detrital vs Grazing Food Chain

There are two types of food chains as detrital and grazing food chain. A detrital food chain mostly consists of decomposers or microorganisms, and the main source of energy of a detrital food chain is the dead remains of organisms. A grazing food chain is based on photosynthetic plants. Therefore, plants are the main source of energy in grazing food chains. Generally, grazing food chains are larger than detrital food chains. Moreover, grazing food chains can have herbivores and carnivores. Thus, this summarizes the difference between detrital and grazing food chain.

Reference:

1. “46.1B: Food Chains and Food Webs.” Biology LibreTexts, Libretexts, 15 Aug. 2020, Available here.

Image Courtesy:

1. “Food Chain In Taiga” (CC0) via Pixy
2. “Leaf to mongoose food chain” By Siyavula Education (CC BY 2.0) via Flickr