Food chain is defined as a linear sequence of organisms that begins from producer organisms and ends with decomposer species. Connection of multiple food chains is called a food web. While the food chain follows a single path, the food web has multiple paths. Food chains help us understand how organisms are connected with each other. Both the food chain and food web are an integral part of our ecosystem. Let us study the differences between a food chain and food web.
Scientifically, the food chain can be defined as a chronological pathway/order which shows the flow of energy from one organism to the other. Energy tends to flow in a particular pathway in a community which comprises producers, consumers, and decomposers. Energy can neither be created nor destroyed. But through different organisms, it moves from one level to the other.
A food chain displays a single pathway from the producers to the consumers, it describes how the energy flows in this pathway. Food travels through different levels in the animal kingdom. Studying a terrestrial ecosystem helps us understand the food chain better.
Food Chain in Terrestrial Ecosystem
The sun is the initial energy source. It is utilized by producers/plants for creating their own food, which helps them grow. The process is called photosynthesis. The next organism in the chain is the consumer. They feed on food produced by plants, accumulating energy.
The organisms that consume primary producers are called primary consumers. This could be a herbivore like a cow or goat or could even be a man in a terrestrial ecosystem. When a man consumes a goat or for that matter any other animal, he becomes the secondary consumer.
The food chain keeps moving up as energy flows from one level to the other. Each level in the food chain is known as trophic level. The different trophic levels in a food chain includes primary producers, primary consumers, secondary consumers, tertiary consumers and quaternary consumers.
Example of Food Chain
Grass (Producer) — Goat (Primary Consumer) — Man (Secondary Consumer)
In a detritus food chain (DFC), dead organic matter marks the beginning of a food chain. Decomposers including fungi and bacteria feed on organic matter for meeting energy requirements. Decomposers secrete digestive enzymes which help in breaking down the organic matter into inorganic materials.
Food Web
Several interconnected food chains form a food web. Through different organisms, the food web provides a realistic representation of energy flow in an ecosystem.
A single organism gets eaten by many predators or vice-versa. When there are several trophic levels which are interconnected, the food chain will not be able to represent the energy flow in a proper order. This is where a food web comes handy, it displays the interaction between various organisms in an ecosystem.