Principles of ecosystem function?

• Ecosystem functions through the input of energy mainly solar radiation. L. Lindeman has formulated principles about the relationship between trophic levels within a natural ecosystem.
  • Principle 1: As the distance between the organisms of a given trophic level and the initial source of energy (trophic level one) increases, the probability of the organisms to depend exclusively on the preceding trophic level for energy decreases.
  • Principle 2: The relative loss of energy due to respiration is progressively greater to higher trophic levels because the species at higher trophic levels are relatively larger in size and have to move and work for getting food and therefore more energy is lost due to respiration.
  • Principle 3: Species at progressively higher trophic levels appear to be progressively more efficient in using their available food supply.
  • Principle 4: Organisms at higher trophic levels are ‘generalists’ in their feeding habit and they are most efficient in using their available food supply.
  • Principle 5: Food chains tend to be reasonably short. Because the loss of energy is progressively higher for higher trophic levels and species at higher levels tend to be less discrete.

The chemical (inorganic) and organic substances are circulated among the various components of the biosphere through a series of closed system of cycles collectively known as ‘biogeochemical cycles’.

• The ecosystem productivity (referred to as the rate of growth of organic matter per unit time by autotrophs at trophic level one) depends on two factors:
  • The availability of the amount of solar radiation to the primary producers at trophic level one.
  • The efficiency of plants to convert solar energy into chemical energy.
• The ‘normal’ or ‘uneventful’ ecosystem attains its stability through ‘homeostatic mechanisms’ There is inbuilt self-regulating mechanism in a natural ecosystem through which any change caused by external factors in the ecosystem is counterbalanced by the responses of the ecosystem to the change in such a way that ultimately ecosystem or ecological stability is achieved.