Definition of Food Chain
A food chain refers to the sequence of events in an ecosystem, where one living organism eats another, and that organism is then eaten by another larger organism. Thus the flow of nutrients and energy from one organism to another at different trophic levels forms a food chain.
➤ Thus, "A food chain is the sequence of different types of organisms through which food energy flows in an ecosystem. The flow of energy through organisms in a food chain is unidirectional. For example, plants (producers) are eaten by rats. The mouse is eaten by the snake and the snake is eaten by the eagle."
Read more - What is Ecology? : Classification, Branches
Composition of Food Chain
Read more - What is Ecology? : Classification, Branches
Composition of Food Chain
A food chain begins with producers, i.e., plants is continued by consumers, i.e., animals of varying orders and is completed by decomposers or reducers, namely bacteria and fungi. But the reducers are often missing since they operate at all the levels of a food chain. Thus, a food chain always begins with green plants and ends with a larger animal like lion.
.jpg "Food Chain : Producers → Herbivores → Carnivores")
➤ In animal's group, the plant-eating animals or herbivores are the primary consumers. The herbivores animals are fed upon by the secondary consumers which may include carnivores (animals that eat meat) or omnivores (feed on plants and animal both).
Various Types of Food Chains
1. Grazing Food Chain : This type of food chain starts from green plants and ends at carnivores by passing through herbivores animals. In herbivores, digested food can be stored in many forms such as carbohydrates, proteins or fats.
➤ The final distribution of energy in herbivores is through three routes –
Autotrophs (Producers) → Herbivores (Primary consumers) →Primary Carnivores (Secondary consumers) → Secondary Carnivores (Tertiary consumers)
Read More - Pond or Lake Ecosystem : definition, type
The ecosystem in which herbivores are numerous, the food chain is small but the ecosystem in which carnivores are numerous, the food chain is long.
Read more - Terrestrial Adaptations in animals
Some common food chain are as follows:
Animal foods flow chain
Land Food Chain
Food chains of many animals come under this, which are as follows
In a simple form, a food chain may be represented as under:
Producers →Herbivores →Carnivores
.jpg "Food Chain : Producers → Herbivores → Carnivores")
➤ The primary source of energy is the Sun. Green plants alone are capable of capturing solar energy, which they use to reduce carbon from carbon dioxide. This carbon forms carbohydrates, fats and proteins, which are the fuels of life. The energy catches in these compounds is stored in plants and forms the primary source of energy supply to all other living organisms. Thus, plants are the producers of ecosystems.
➤ In animal's group, the plant-eating animals or herbivores are the primary consumers. The herbivores animals are fed upon by the secondary consumers which may include carnivores (animals that eat meat) or omnivores (feed on plants and animal both).
Read more - Energy Flow in an Ecosystem
Various Types of Food Chains
Basically there are two types of food chains which are-
- grazing food chain
- detritus food chain
➤ The final distribution of energy in herbivores is through three routes –
1. Respiration
2. Decay of organic matter by bacteria and other decomposers
3. Consumption by carnivores.
2. Decay of organic matter by bacteria and other decomposers
3. Consumption by carnivores.
➤ Primary carnivores or secondary consumers eat herbivores or primary consumers. Similarly, secondary carnivores or tertiary consumers eat primary carnivores. The total energy consume by primary carnivores (or grass tertiary production) is derived entirely from the tissues of herbivores.
➤ Its disposition into respiration and further consumption by other carnivores is similar to that of herbivores. The energy flow of grazing food chain can be described in terms of trophic levels as follows:
Read more - What is food web?
➤ The food chain demonstrates the amount of energy found that at any trophic level, the transfer of energy from one trophic level to the next and the amount of energy lost from the grazing food chain. Further,
Producer → herbivore → carnivore chain is predator chain.
➥ The predatory food chain starts with herbivores and goes from smaller to large predators, i.e., herbivores are primary consumers, and predators as the number decreases at each level in the food chain. Predators of first level are smaller than those of second level.
➥ The parasite food chain also starts with the herbivores but food energy passes from larger to smaller organisms. The large animals are the host and the small animals which fulfill their nutritional requirements from the host are parasites.
➥ The predatory food chain starts with herbivores and goes from smaller to large predators, i.e., herbivores are primary consumers, and predators as the number decreases at each level in the food chain. Predators of first level are smaller than those of second level.
➥ The parasite food chain also starts with the herbivores but food energy passes from larger to smaller organisms. The large animals are the host and the small animals which fulfill their nutritional requirements from the host are parasites.
Read More - Pond or Lake Ecosystem : definition, type
2. Detritus Food Chain : The organic wastes, exudates and dead matter derived from the grazing food chain are termed detritus. The energy contained in this detritus is not lost to the ecosystem rather it was serves as the source of energy for a group of organisms derivers that are separate from the grazing food chain, and generally termed detritus food chain.
➤ In detritus food chain are many and include algae, bacteria, slime moulds, actinomycetes fungi, protozoa, insects mites, crustacea, centipedes, molluscs, rotifers, anneid worms, nematodes and some vertebrates.
A general food chain may be as follows:
Producers → P.C. → S.C. → T.C. → Decomposers
A general food chain may be as follows:
Producers → P.C. → S.C. → T.C. → Decomposers
The ecosystem in which herbivores are numerous, the food chain is small but the ecosystem in which carnivores are numerous, the food chain is long.
Read more - Terrestrial Adaptations in animals
Some common food chain are as follows:
Animal foods flow chain
Land Food Chain
Food chains of many animals come under this, which are as follows
➤ Grass → Cattle → Man
➤ Grass → Rabbit → Fox → Wolf → Tiger
➤ Vegetation → Squirrels → Bear → Wild Cat → Tiger
➤ Forest/Grass → Zebra → Lion
➤ Grass → Grass hopper → Bird → Eagle
Pond water food chain
This food chain is small because it is found only in the pond.
➤ Grass → Rabbit → Fox → Wolf → Tiger
➤ Vegetation → Squirrels → Bear → Wild Cat → Tiger
➤ Forest/Grass → Zebra → Lion
➤ Grass → Grass hopper → Bird → Eagle
Pond water food chain
This food chain is small because it is found only in the pond.
Phytoplankton → Insect larva→ Carnivore insects → Frog → Snake
Importance of Food Chain
➤ There is unidirectional flow of energy from sun to producers and then to a series of consumers in a food chain.
A food chain always begins with photosynthesis and ends with decay.
➤ The shorter a food chain, the more efficient it is. The more steps it has, the greater is the wastage of energy.
➤ The size of any population is determined by the number of trophic levels in a food chain. With the decrease in useful energy at each step, there is a decrease in the population size. The size of a population of quaternary consumers is less than of tertiary consumers and that of tertiary consumers is smaller than secondary consumers.
Read more - Aquatic Adaptations
Ocean food Chain
Phytoplankton → Zooplankton → Small fishes → Large fishes → Shark Sea food chains are long.
Importance of Food Chain
Following important ecological principles emerge from the study of food chain:
➤ There is unidirectional flow of energy from sun to producers and then to a series of consumers in a food chain.
A food chain always begins with photosynthesis and ends with decay.
➤ The shorter a food chain, the more efficient it is. The more steps it has, the greater is the wastage of energy.
➤ The size of any population is determined by the number of trophic levels in a food chain. With the decrease in useful energy at each step, there is a decrease in the population size. The size of a population of quaternary consumers is less than of tertiary consumers and that of tertiary consumers is smaller than secondary consumers.
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