In any ecosystem there is transfer of food from one organism to another organism. One organism act as an food source for anpther organism. This transfer of food in a sequence forming a chain referred to as food chain. This chain is the result of interdependency. There are mainly two types of food chain exists in an ecosystem. These are:
(a) Grazing food chain (GFC): This food chain starts with the green plants i.e., producers at the first trophic level in any ecosystem. In case of aquatic ecosystem, the GFC is the major system for energy flow. In this food chain energy comes from the sun. A simple grazing food chain is shown below:
(b) Detritus Food Chain (PFC): At starts with the dead organic matter with the decomposers. These organisms are called saprophytes at first trophic level for example bacteria and fungi. In an terrestrial ecosystem a large amount of energy flows through this type of food chain. In this type of food chain energy comes from organic matter or detritus. Detritus food chain is connected with the grazing food chain at various levels.
Difference between Food chain and Food web:
|
Food Chain |
|
Food Web |
| 1 |
It represents the linear flow of food energy from one organism to another. |
1 |
It represents the many inter connecting food chains in an ecosystem. |
| 2 |
It is single undirectional energy flow. |
2 |
It is a connection of, several interconnected food chains. |
| 3 |
It consists of 4-5 trophic levels. |
3 |
It consists of many more number of trophic levels.
|
| 4 |
Whole food chain is disturbed of one disturbance occurs at any level. |
4 |
It does’nt affected by a single disturbance in a single trophic level. |
| 5 |
It can be of two main types grazing and detritus food chain. |
5 |
No such type of differentiation occurs in a food web. |
Diagram of Food Chain:
Grass → Grasshopper → Frog → Snake → Eagle
