Illustration of a food chain
The food chain is the pathway along which food is transferred from one trophic or feeding level to another.
Energy, in the form of food, moves from the producers to the herbivores to the carnivores. Only about 10 percent of the energy stored in any trophic level is converted to organic matter at the next trophic level. This means that if you begin with 1,000g of plant matter, the food chain can support 100g of herbivores (primary consumers), 10g of secondary consumers, and only lg of tertiary consumers. As a result of the loss of energy from one trophic level to the next, food chains never have more than four or five trophic levels.
Examples of food chain: An example of simple food chain operating in a grassland or forest. In a grassland or forest, there is a lot of grass. This grass is eaten up by animals like deer,and deer is then consumed by a lion.
This food chain tells us that grass is the starting point of this food chain. The grass is eaten up by deer and the deer is then eaten up by a lion. In this food chain, grass is the producer which uses sunlight energy to prepare food like carbohydrates by the process of photosynthesis. This grass is then consumed by a herbivore called deer. And the deer is consumed by a carnivore called lion. The food chain represents a single directional or unidirectional transfer of energy.
In the above example, the food chain tells us that the transfer of energy takes place from grass to deer and then to lion. It cannot take place in the reverse direction form lion to deer to grass. The study of food chains in an area or habitat helps us in knowing various interactions among the different organisms and also their interdependence.
The food chain is the pathway along which food is transferred from one trophic or feeding level to another.
Significance of food chains
- The study of food chains helps in understanding food relationship and interdependence among various organisms in an ecosystem.
- The mechanism of transfer of food, energy and nutrients through various components of nature can also be studied.
- The effect of the use of pesticides on the ecosystem can be studied. As several of them are not biodegradable it goes on accumulating at every trophic level. Hence consumers at higher trophic levels will consume more poison along with their food. This phenomena is known as biological magnification.
- Indiscriminate use of DDT and other pesticides has an adverse effect on the food chain and consequently disturbs the ecosystem.