The function of an ecosystem involves the volume and the rate at which various materials circulate and the rate at which energy flows through it. The study also includes the processes by which living organisms change the abiotic environment the processes by which non-living environment affect living organisms and the events by which population levels of organisms are regulated.
The function of ecosystem describes the flow of energy and the cycling of nutrients. This includes the several aspects of an ecosystem,
(i) Energy flow
(ii) Food chain
(iii) Diversity pattern in time and spax
(iv) Nutrient cycles
(v) Development and evolution
The solar energy is converted into chemical energy through photosynthesis by plants. These green plants are grazed by heterotrophy. This shows not only the chemical energy in the form of carbohydrates, fats and proteins but a host of other nutrients are transferred into herbivores. Such a process continues up to the decomposer level through the carnivores.
The energy trapped by green plants when transferred from one food level or tropic level to another depicts the loss of energy at each transfer along the chain.
The energy that posses from herbivore to carnivore do not pass back to herbivores from carnivore and that energy movement is unidirectional unlike the nutrients/materials in an ecosystem.
It is noticeable that the transfer of nutrients along with chemical energy does not indicate loss of nutrients like that of energy. It is because that the fecal matter, excretory products and dead bodies of all plants and animals are broken down into inorganic nutrients by decomposers and eventually returned to the ecosystem for reuse by the autotrophy.
The interaction of its components involving the flow of energy and cycling of materials are shown in the Fig. 4.
The two ecological processes of energy flow and mineral cycling involving interaction between the physico-chemical environment and the biotic communities may be considered the heart of the ecosystem dynamics. In an ecosystem, energy flows in non-cyclic manner (unidirectional) from sun to the decomposers via producers and macro-consumers (herbivores and carnivores) whereas minerals keep on moving in a cyclic manner.