Difference Between Food Chain and Food Web

Introduction image

Difference between food chain and food web is mainly due to the following factors:
Network of links: Food chain is an one-way pathway that includes a linear network of linking organisms. In contrast, food web is a complex pathway that indicates a number of food chains together to show how the organisms are interlinked with each other to survive.

Trophic level: A trophic level depicts energy and nutrient flow in the ecosystem, generally in a sequence from producer, to consumer and finally to the decomposers. A food chain can represent 4-5 trophic levels starting from the producers (green plants), consumers (herbivores, carnivores, omnivores, predators) to the decomposers (fungi and bacteria).

In contrast, a food web connects different food chains or the organisms distributed at different trophic levels of our ecosystem, where each link is connected to at least two other relative organisms.

Content: Food Chain Vs Food Web

  1. Comparison Chart
  2. Definition
  3. Trophic Levels
  4. Energy Transfer
  5. Key Differences
  6. Conclusion

Comparison Chart

PropertiesFood chainFood web
MeaningIt can define as a single pathway that simply shows the energy and nutrient flow between different trophic levels, starting from producers, consumers and finally to the decomposers It can define as a combination of numerous food chains and trophic levels that represents an ecological community where the organisms are linked with each other to feed upon
PathwayIt represents a linear pathway It forms a lattice pattern, where the different organisms are interrelated with each other
Number of chainsIt has a single chain It has interconnected food chains
Number of linksIt has 4-5 links in a single chainIt has different interconnected links in a number of food chains that constitutes a food web
Effect on adaptability and competitivenessIt has no effectIt has a major effect on improving the adaptability and competitiveness of the organisms
Members of higher trophic levelFeed upon single type of organismsFeed upon variety of organisms

Definition of Food Chain

It can define as a one way representation of the energy transfer between the organisms from the lower to the higher trophic level organisms. In a food chain, the organisms are grouped into three trophic levels, namely producers, consumers and decomposers. It simply make us understand that who-eats-who.

diagram of food chain

Definition of Food Web

It can define as the geographical representation of the ecological community that forms by the combination of interconnecting food chains. Food web shows different kinds of ecosystems (terrestrial and aquatic) altogether to give us an idea about the competitiveness and adaptability of the organisms belonging to different trophic level.
diagram of food web
The distribution of organisms in a trophic level is same in both food chain and food web, that we will discuss below.

Trophic Levels

Organisms in a food chain are distributed at different trophic levels, as explained below:

Producers

These are the autotrophic plants, which get energy from the sunlight and minerals or nutrients from the soil. Therefore, the first trophic level includes all the autotrophs and photosynthetic single celled organisms, which primarily carry out photosynthesis to form organic food “glucose” by using sunlight, carbon dioxide, and water. Seaweed, phytoplankton that are found in the aquatic habitats are also autotrophs.

Consumers

It includes the organisms that feed upon the producers and constitute the second trophic level. It can be categorized further into:

  • Primary consumers: Herbivores like deer, cow, goat etc. are the members of this category, those are fully dependent upon the autotrophs.
  • Secondary consumers: These eat the herbivores.
  • Tertiary consumers: These feed upon the secondary consumers.
  • There can be quaternary consumers as well before it reaches to the top or apex predators.

Consumers broadly categorize into carnivores and omnivores. Carnivores are the animals that feed upon the other animals, while omnivores are the animals that can feed upon both plants and animals. Carnivores includes, lion, tiger, fox, eagle etc. human beings are the best example of omnivores who consume plant source (vegetables and fruits), animals and animal products (meat, milk, and eggs), mushrooms (a form of fungi).

Detritivores/Decomposers

Detrivores represent the third trophic level of food chain those eat the plant and animal remains like vultures eat dead animals. Decomposers (fungi and bacteria) completes the cycle of  life by turning out the organic wastes of plants and animals into inorganic materials, that in turn used up by the plants. Thus, it starts a whole new food chain.

Energy Transfer Between the Trophic Levels

Energy transfers from the lower trophic organisms to the higher trophic organisms feed upon the lower trophic organisms or prey’s body to get energy and nutrients. Due to competitiveness between different organisms, the energy transfer is inefficient for the higher organisms that limits the further flow of food chain.

Some part of energy is stored as biomass or cellular energy in a food chain, from which only about 10% goes to the next trophic level. Thus, fractions of energy transfer lasts generally three to six trophic levels, as only little energy flow to support higher trophic organisms.

Key Differences Food Chain and Food Web

  1. Food chain define as a single pathway that simply shows the energy and nutrient flow from one to four trophic levels and finally to the decomposers. Food web can define as a combination of numerous food chains and trophic levels that represents an ecological community where the organisms are linked with each other to feed upon.
  2. The pattern of food web is generally depicted by a lattice arrangement, where the different organisms are interrelated with each other forming a net-like cycle. In contrast, a food chain follows a linear pathway.
  3. The organisms in a food chain are linking at different trophic levels through a single chain or cycle, whereas food web forms via interconnecting food chains.
  4. In a food chain, higher organisms depends upon the single kind of lower organisms. In contrast, the higher trophic level organisms feed upon variety of organisms associated with different kinds of ecosystem.

Conclusion

Therefore, we can conclude that the food chain and food web represent a food cycle of our ecosystem, where the organisms are dependent or interlinked with each other for their survival. The survival of organisms depends upon the nutrients and energy, they harnessed from their lower trophic level.

However, 80-90% of energy is lost as heat dissipation, and the remaining 10%-20% of the biomass passes to the next organism. On each transfer, the biomass decreases by the increasing entropy.

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