Food chain
[edit] Introduction to food chain in ecosystem
Food chain consists of the sequence of populations of an Ecosystem which allows the transfer of food and Energy through it. Each member becomes the food of later species of member. The food chain is also known as a predator food chain. It consists of producers, consumers and the decomposers.
[edit] Producers, Consumers and Decomposers
[edit] Producers
Organisms, such as plants, that produce their own food are called autotrophs. They make the food by the process of photosynthesis from the inorganic materials. It includes all green plants .They are called producers because all of the species of the ecosystem depend on them. They are also referred as the transducers as they can convert one form of energy to the other form. The organic compounds which are formed play an important role in the building of bodies and help in the release of energy. They make up the bulk of the food chain or web.
[edit] Consumers
Consumers are heterotrophic organisms. They obtain food by eating other organisms. There are different levels of consumers. The consumers can be first, second, tertiary and the fourth order. Herbivore such as deer, mouse, rabbit, squirrel and cattle are primary consumers. Some of them also occurs in the aquatic areas and include the crustaceans, mollusks and protozoan. The secondary consumers are also known as the primary carnivore such as frog, bird, fish, snakes, jackal and wild cat. There are few organisms which feed on the primary carnivore and are known as the tertiary consumers. It includes the owl, fish, tiger and lion. These are also known as secondary carnivores. They act as a food for the tertiary carnivore. There are certain carnivores which cannot become food for the other organism. They occur at the top of food chain. It includes the lion. The food chain ends at the herbivore animals.
[edit] Decomposers
Decomposers are nature's recyclers. They break down the organic matter found in the dead bodies of plants and animals. The term 'organic matter' refers to the matter that comes from living organisms. Decomposers are chiefly the micro-organisms such as bacteria and fungi in the form or yeasts and moulds that break down bodies of dead organisms and release compounds that can be used by producers. Decomposers are necessary since they recycle the nutrients to be used again by producers.
[edit] Terrestrial and Marine Food Chain in Nature
The food chains occur in the land as well as in the water. The pond is the most common place of their residence in water. In the land the grass is eaten by the grasshopper. The grasshopper is eaten by the frog and the frog is eaten by the snake. Ultimately, the snake is eaten by the peacock. The vegetation is eaten by the insect. The insect is eaten by the predator insect and the predator insect is eaten by the insectivorous bird. Ultimately, the insectivorous bird is eaten by the hawk. The vegetation is eaten by the rabbit. The rabbit is eaten by the fox and the fox is eaten by the wolf. Ultimately, the wolf is eaten by the tiger.
[edit] What is the difference between the 'Food Chain' and 'Food web?'
A popular misnomer, the 'food chain' is not actually a linear chain but a complex web. Energy is passed from one organism to another in a complex network like a spider's web.
[edit] How have humans affected the food chain?
When we spray pesticides, we put the food chain in danger. By breaking one link on the chain means all of the organisms above that link are in threat of extinction (like the domino effect). By hunting animals nearly to extinction, everything above the animal in the food chain is put in danger. A 'chain reaction' in the food chain can be perilous! Since the food chain provides energy that all living things must have in order to survive, it is imperitive that we protect it.
[edit] Types of food chain
The types of food chain are as follows,
1) Grazing food chain
2) Parasitic food chain
3) Saprophytic food chain
4) Detritus food chain
[edit] Grazing food chain
Grazing food chain begins at the producer level and extends up to top carnivores. Usually the size of the consumer is comparatively large at successive levels.
[edit] Parasitic food chain
Parasitic food chain also begins with the producer level. Unlike the predator food chain, here the consumer is smaller in size. Passing of food energy from larger to smaller organisms is the characteristic feature of this food chain. A larger organism from which food is derived is called the host. Smaller organism which obtains food is called as the parasite.
[edit] Saprophytic food chain
Some animals are in the top carnivore’s animals such ashawk, lion, vulture and osprey that have no natural food enemy. The transfer of food energy from dead organic matter of decaying animal and plant bodies to micro organisms is known as saprophytic food chain.
[edit] Detritus food chain
The decomposed body of producers is called as detritus. The detrivores are eaten by various carnivores like aquatic bird.
[edit] Flow of energy through food chain
The energy utilized at each level of food chain is less than the total energy.
a) Pyramid of energy:
There is a decrease in energy absorbed from producers till tertiary consumers. The greater part of energy from sun is dissipated as heat by the plants. Therefore, the net energy decreases in the form of pyramid.
b) Pyramid of biomass
Biomass is the estimated mass of the total populations calculated by the product of the total people count with average weight of each person. This is also similar to pyramid of energy.
c) Pyramid of numbers
The pyramid of numbers is calculated by the number of species at each trophic level of food chain in a particular area. This is also same as pyramid of energy.
