Food Chains and Food Webs

Last Updated : 23 Jul, 2025

Food Chain and Food Web both show the direction of the flow of energy and nutrients in the ecosystem. The food chain is a linear representation of organisms along the trophic level, while the food web is multiple interconnected food chains.

The food chain and food web make us understand the interaction among the species and the way they are interdependent. Overall it gives an impression of the workings of the ecosystem and the balance it maintains within. In this article, we will also study the difference between food chain and food web.

Table of Content

What is a Food Chain?

A food chain represents the flow of energy and nutrients among different organisms in an ecosystem. It tells us how energy and nutrients are transferred from one trophic level to another and how the organisms interact in an ecosystem. In a food chain, each organism represents a particular trophic level according to its food behavior.

Producers are living organisms that produce their own food by utilizing solar energy through the photosynthesis process. For example, plants, green growth, etc.
Consumers are living organisms that cannot produce their own food and obtain energy by consuming other organisms. For example, lions, tigers, wolves, foxes, etc.
Decomposers are the organisms that breaks down dead organic matter and recycles nutrients back into the ecosystem. They are present at the last stage of the food chain, that breaks down waste and remains from all other trophic levels. For example, bacteria and fungi.

The food chain demonstrates how the energy and nutrients flow in an ecosystem. It can be explained as follow:

Energy Flow

Energy enters an ecosystem mainly from the sun. This energy is used by the producers and converts it into organic compounds like glucose. Herbivores (primary consumers) consume these producers and obtain a portion of this energy. Subsequently, carnivores (secondary and tertiary consumers) consume herbivores or other carnivores, transferring energy to the higher trophic level in the food chain. With each transfer, some energy is lost as heat during metabolism, limiting the energy available to higher trophic levels.

Nutrient Cycling

With the consumption of the food nutrients, within the organic matter are released. When organisms die, decomposers (bacteria, fungi) break down the organic matter, releasing nutrients like carbon back into the ecosystem. These nutrients are then taken up by producers, completing the nutrient cycle. This recycling of nutrients is essential for the growth of new organisms and the continuation of the food chain.

Energy flows unidirectionally through trophic levels in a food chain, with energy decreasing at each transfer. Nutrients cycle through each trophic level ensure a constant supply of essential nutrients for life within an ecosystem.

Food Chain Diagram

The food chain diagram is given below:

Types of Food Chain

Food chains are of two types on the basis of the primary energy source: Detritus and Grazing Food chain.

Grazing Food Chain

The primary energy source is the green plants or producers. These plants utilize sunlight and convert it into chemical energy through photosynthesis. Herbivores feed on these plants for energy. The energy then flows through the food chain as carnivores (animals that eat other animals) consume herbivores, and so on. The food chain starts with producers and moves up through various trophic levels.

Sun-> Autotrophs-> Herbivores-> Small Carnivores-> Large Carnivores-> Top Predator

Detritus Food Chain

This food chain starts with dead organic material. The Detritus food chain starts decomposers like bacteria, algae, fungi, etc, which decompose the organic material like the detritus of plant, and dead animals. Decomposers are then consumed by detritivores, which are organisms that feed on decomposed organic matter.

As detritivores are eaten by predators or scavengers, the energy derived from the detritus is transferred through the food chain. Detritus food chains play an important role in recycling nutrients and breaking down organic material.

Also Read: Difference Between Grazing and Detritus Food Chain

Food Web

The food web represents multiple interconnected food chains and the complex relationships between producers, consumers, and decomposers. Organisms are arranged into different trophic levels, with producers at the base, followed by primary, secondary, and tertiary consumers. All the organisms, including predators, prey, and scavengers, interact within this food web, which influences the population dynamics.

Decomposers break down dead matter, recycling nutrients back into the ecosystem. Each level in the food web depends on the lower level for energy and nutrients. Change in one trophic level impacts the other tropic levels or the whole food web. It shows the dependency of one trophic level on one another and the importance of biodiversity.

Food Web Diagram

The diagram showing the food web is given below:

Food-web

10 Percent Energy Rule

Producers can utilise only 1% of the sunlight through photosynthesis to prepare their food. The energy is lost in the form of heat to the environment and in metabolism when plants are eaten by the next trophic level. This rule highlights the efficiency of energy transfer and the challenges of supporting higher trophic levels in ecosystems.

The 10 percent energy rule states that of the energy available at one trophic level, only about 10 percent of the energy is transferred to the next trophic level. Because of this 10% energy rule, the food chain can be sustained only up to 4-5 trophic level.

Difference between the Food Chain and Food Web

The difference between the food chain and food web in tablular form is given below:

Features	Food Chain	Food Web
Definition	It represents a linear sequence of organisms where each feed on the one below	It represents the complex interconnection of multiple food chains within an ecosystem.
Structure	Single direction of energy flow	Interconnected food chain representing multiple pathways.
Trophic Levels	Includes a few trophic levels.	Includes multiple trophic levels.
Interactions	Represents one feeding relationship.	Represents multiple feeding relationships.
Energy Flow	Energy flows in a single direction through levels.	Energy flows in multiple directions.
Examples	Grass → Rabbit → Fox Phytoplankton → Zooplankton → Fish	Plants → Herbivores → Carnivores → Decomposers → Multiple species interactions
Importance	Helpful for understanding energy flow in a simplified manner.	Essential for studying ecosystem stability, species relationships, etc.

Also Read: Difference between the Food Chain and Food Web

Why are Humans not Apex Predators?

Humans are not at the top of the food chain because of their wide variety of diets, including both plant-based foods and animals from various trophic levels. Animals at the apex mainly consume other carnivores, and humans can consume plants, herbivores, or carnivores. Moreover, ecosystem is complex and interconnected, involving numerous species with energy and nutrient flows. While humans have significant impacts on ecosystems, their role is influenced by cultural, ecological, and technological factors, making their position in the food chain complex and multifaceted.

Importance of Food Chain and Food Web

The food chain and food webs form the basic structures that determine the interactions between species and the flow of energy and nutrients within ecological communities. It holds several significance, including:
Both the food chain and food web demonstrate the flow of energy from one trophic level to another in a complex manner. This energy flow determines the various ecological processes and maintains the circulation of nutrients within the ecosystem.
Species in a food chain are interdependent. This interdependence helps to maintain the population of any one species in the ecosystem.
The food chain help us understand predator-prey relationships and how the population is regulated.
The interconnected relationship within food webs helps to maintain the ecosystem services.
Food web is an indicator of the health of the ecosystem.
Food web help us in conservation efforts by identifying keystone species and vulnerable points.

Conclusion - Food Chain and Food Web

Both the food chain and food web illustrate how energy and nutrients move through ecosystems, showing interactions among species and their interdependence. Undestanding food chain and food webs help us grasp ecosystem dynamics, population regulation, and conservation efforts, highlighting the importance of understanding these ecological structures for maintaining ecosystem health and biodiversity.

Also Read:

Energy Flow of Ecosystem
Trophic level Diagram
Ecological Pyramid – Definition, Types, Importance, Limitations
Our Environment – Notes CBSE Class 10

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