Functioning of ecosystem

 Functioning of Ecosystem

The main functions of an ecosystem are as follow:

Food Chain

* The feeding of one organism upon another in a sequence of food transfer is known as a food chain.  Another definition is that it is the chain of transfer of energy ( which typically comes from the Sun) from one organism to another.  A simple food chain is like the following 

                       Grass>Insect>Frog>Snake>Hawk

* Except in deep-sea hydrothermal ecosystems, all food chains start with photosynthesis and end with decay.

Food Web

* A network of food chains or feeding relationship by which energy and nutrients are passed on from one species of living organism to another is called Food Web.

*A food web is represented by a graphical description of feeding relationship among spices in an ecological community, e.g. of  who eats whom.  It is also a means of showing how energy and materials (e.g. carbon) flow through a community of spices as a result of these feeding relationships.

*  Trophic Levels  Trophic levels are  the feeding position in a food chain such as primary producers, herbivore, primary carnivore etc.  Generally, green plants form the first trophic level, the producers.  Herbivores form the  second trophic level, while carnivores and omnivores form the third and even the fourth trophic levels.

*   Ecological Pyramids   An ecological pyramid is a graphical representation designed to show the number of organisms, energy relationships and biomass of an ecosystem.  They are also called Elton pyramids after Charles Elton, who developed the concept of ecological pyramids.

*     Pyramid of Biomass  A pyramid of biomass is a representation of the amount of energy contained in biomass, at different tropic levels for a particular time.  It is measured in grams per square meter or calories per sq. m.

There are two types of biomass pyramids, which are as follow:

i)  Upright Pyramid   An upright pyramid is one where the combined weight to producers is larger than the combined weight of consumers. e.g. forest ecosystem.

ii)  Inverted Pyramid  An inverted pyramid is one where the combined weight of producers is smaller than the combined weight of consumers. e.g. an aquatic ecosystem.