Introduction

In all types of ecosystems, green plants convert solar energy into chemical energy. This chemical energy is bound to food or organic compounds such as carbohydrates, fats, proteins, etc. All the members of the living world have to depend on green plants for energy. That is why the amount of energy available at the highest food level of a region depends on the ability of green plants to bind solar energy. Herbivores take green plants as food. And herbivores are preyed upon by other carnivores. Thus energy gradually reaches from the lowest food level to the highest food level. This implies that all species of organisms, from the producer to the tertiary consumer, are bound together in a chain to collect food. This is the food chain. In this food chain, one type of organism helps another organism to survive (1) & (4).

What is a food chain?

In the ecosystem, food energy is transferred at a declining rate from the lowest trophic level (producer) to the highest trophic level (decomposer) among the various food and consumer groups. The flow of this chained periodic energy is called the food chain.

According to scientist Odum, the process by which food energy flows from producer to consumer in different stages based on the relationship between food and consumer is called the food chain.

Grass → Grasshopper → Frog → Snake → Hawk

Each food chain has several levels of nutrients. These are called trophic levels. The first food layer of any food chain is made up of autotrophic organisms. This food layer is called the producer level. Subsequent food layers are formed by different types of consumers. Consumers eat on producers or organisms that are dependent on producers. This is because they are called heterotrophs. Biosphere consumers are divided into three groups (3).

• Herbivores

Herbivores take only plants or parts of plants as food. Such as deer, cow, sheep, etc.

• Carnivores

Such predators survive only by eating other animals. Example lions, tigers, etc.

• Omnivores

Consumers who eat both plants and animals are called omnivores. Such as humans, bears, etc. (3) & (5).

Structure of the food chain

The structure of the food chain is much like a chain. Autotrophic plants or producers convert solar energy into chemical energy in the body during food preparation and bind it to ATP. This type of chemical energy is bound in food as potential energy. The primary consumer takes food made by producers. As a result, energy is transformed into the body of the primary consumer. The secondary consumer eats the primary consumer and that energy flows from the primary consumer to the body of the secondary consumer. Thus food energy is transferred from the secondary consumer to the tertiary or final consumer level. In this way, energy is transferred from the producer to the first, second, and tertiary stages of the consumer and forms the food chain (3) & (5).

Some interesting facts about the food chain

1. The nature of the food chain is often complex. The combination of many food chains with the environment can be seen.
2. Green plant refers to the producer of the food chain. They form the primary layer or base layer of the food chain.
3. As the food chain rises from the primary level, the number of organisms decreases, and the size of the organism increases.
4. When the biodiversity of the ecosystem is high, the food chain becomes complex. As a result, the food chain forms the food web.
5. With one or two exceptions, the food chain has three to five layers.
6. The energy flow in the food chain from the primary trophic level to the tertiary trophic level is one-way.
7. Some food chains start without green plants. Such as parasitic food chains.
8. At each level of the food chain, there is some loss of energy. That means 100% of energy does not flow from one level to the next level.
9. Decomposers are located at each level of the food chain (1) & (4).

Types and examples of the food chain

In nature, the food chain is formed on the basis of energy transmission and food-consumer relationships. The food chain is divided into two parts according to energy transmission. Such as the grazing food chain and the detritus food chain. There are three types of food chains based on the food-consumer relationship. All of these food chains are described below (2) & (5).

According to the transmission of energy

The food chain is divided into two parts according to the transmission of energy from producer to consumer. Such as-

1. Grazing food chain

A food chain in which energy is transmitted step by step from autotroph or producer levels to herbivores and carnivores is called a grazing food chain.

In this case, the producers collect solar energy and bind it to their food. The primary consumer collects the energy in their body by taking that food. The secondary consumer eats the primary consumer and the tertiary consumer eats the secondary consumer to collect energy. As a result, the food chain is formed (2) & (5).

Example

Green plant → Butterfly → Frog → Snake → Peacock

2. Detritus food chain

The food chain in which energy is transmitted step by step from the decomposer to the consumer level is called the detritus food chain (2) & (5).

Example

Scientist Odum has seen an example of this type of food chain based on mangrove leaves. The leaves of red mangroves in the region of South Florida fall into shallow hot water and rots. These rotten leaves are eaten by small aquatic animals. All these animals are called detritus. This type of consumer is eaten by small fish. And finally, those small fish are taken as food by the big fish and form a food chain (2) & (5).

Rotting organic matter → detritus → small carnivorous fish → large carnivorous fish

According to the food-consumer relationship

There are three types of food chains based on the food-consumer relationship. These are-

1. Predator food chain

The food chain that starts from the primary stages of herbivores and ends at the level of larger carnivores based on the food-consumer relationship is called the predator food chain. This food chain starts from the producer and in later stages, the size of the organism increases but their number decreases (1) & (5).

Example

Green plant (grass)    →       rabbit       →        hawk

(Producer)        (Primary consumer)     (Secondary consumer)

2. Parasitic food chain

A food chain in which the food-consumer relationship begins at the center of a larger organism and ends in a smaller animal is called a parasitic food chain. The parasitic food chain is where either the producer or the consumer is parasitized (3) & (5).

Example

Dog → worms → protozoa

3. Saprophytic food chain

The food chain that binds to the saprophytic layer based on energy flow, is called the saprophytic food chain. This food chain begins in the saprophyte and ends in the bacteria (5).

Example

Dead plant → fungi → bacteria

Importance of food chain

The importance of the food chain of the ecosystem to the entire biosphere is immense. It is discussed below (1) & (4).

1. Power supply

The solar energy stored in the producer flows through the food chain at a decreasing rate from the producer to the tertiary consumer. This energy decreases at the rate of 10% of each trophic level. As a result, the number of species at each higher level gradually decreases.

2. Existence of an organism

As a result of having a food chain, every creature at the level of producer, herbivores, carnivores, omnivorous, etc. gets their food. With an uninterrupted supply of food, every living thing survives and thus maintains its existence in the ecosystem.

3. Continued food supply

If the food chain is well organized, there is no shortage of food at every trophic level. As a result of natural disasters or human activities, food supply is disrupted at any level of the food chain and its effects fall on the entire ecosystem.

4. Formation of interaction

The food chain builds a good relationship between the food and the consumer. As a result, the cycle of various organic and inorganic substances continues, which is called the organic geochemical cycle. The food chain helps maintain this cycle, and that is when strong interaction ecosystems are formed. So a strong ecosystem is used for a variety of interaction tasks.

5. Disruptive effects

If the food chain is destroyed, there will be a crisis for the survival of every trophic-level organism as well as the survival of the ecosystem. Even the ecosystem will be ruined forever. For example, if a large number of carnivores are hunted at the third trophic level, the number of herbivores will increase. Then they will eat and destroy the producer class of the ecosystem. The producer zero areas will turn into a desert and the entire ecosystem will be destroyed.

6. Maintains the balance of the ecosystem

If the food chain is active then the ecosystem is well organized and the ecosystem is balanced. The food chain maintains the balance of the ecosystem. Therefore, the existence of the ecosystem is endangered as the food chain is destroyed. So when the food chain is shortened the ecosystem is well organized and the ecological balance is maintained.