Food chain is a linear sequence of organisms which starts from producer organisms and ends with decomposer species. Food web is a connection of multiple food chains. Food chain follows a single path whereas food web follows multiple paths. From the food chain, we get to know how organisms are connected with each other. Food chain and food web form an integral part of this ecosystem. Let us take a look at the food chain and a food web and the difference between them.
In scientific terms, a food chain is a chronological pathway or an order that shows the flow of energy from one organism to the other. In a community which has producers, consumers, and decomposers, the energy flows in a specific pathway. Energy is not created or destroyed. But it flows from one level to the other, through different organisms.
A food chain shows a single pathway from the producers to the consumers and how the energy flows in this pathway. In the animal kingdom, food travels around different levels. To understand a food chain better, let us take a look at the terrestrial ecosystem.
Food chain in a Terrestrial Ecosystem
The sun is the source of energy, which is the initial energy source. This is used by the producers or plants to create their own food, through photosynthesis and grow. Next in this chain is another organism, which is the consumer that eats this food, taking up that energy.
The primary consumers are the organisms that consume the primary producers. In a terrestrial ecosystem, it could be a herbivore like a cow or a goat or it could even be a man. When a goat is consumed by man, he becomes the secondary consumer.
Learn more about Biogeochemical Cycle here in detail.
As the energy goes one level up, the food chain also moves up. Each level in the food chain is called a trophic level. The different trophic levels are Primary producers, primary consumers, secondary consumers, tertiary consumers and quaternary consumers.
Example of food chain
Grass (Producer) —–Goat (Primary Consumer) —– Man (Secondary consumer)
When dead organic matter becomes the starting of a food chain, then it is called the detritus food chain (DFC). The decomposers, which are the fungi and bacteria, feed on the organic matter to meet the energy requirements. The digestive enzymes secreted by the decomposers help in the breakdown of the organic matter into inorganic materials.
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Many interconnected food chains make up a food web. When you look at the larger picture, a food web shows a realistic representation of the energy flow through different organisms in an ecosystem.
Learn more about Components of Ecosystem here in detail.
Sometimes, a single organism gets eaten by many predators or it eats many other organisms. This is when a food chain doesn’t represent the energy flow in a proper manner because there are many trophic levels that interconnect. This is where a food web comes into place. It shows the interactions between different organisms in an ecosystem.
The following diagram shows the energy flow between various organisms through a food web.
Solved Questions For You
Q: Name the common detritivores in an ecosystem. Do they play a significant role? Support your answer.
Ans: Earthworms, dung beetles, and sea cucumbers are some of the common detritivores in an ecosystem. They play a crucial role in the ecosystem, by decomposing the dead organic matter.