The flow of energy

You have already learned about the food chains and the different trophic levels existing in an ecosystem. The green plants convert the solar energy in to chemical energy in the living world. Let us see, how this energy is transferred through the different trophic levels. Analyse the following diagrammatic representation (Illustration I) and discuss:

· How much amount of solar energy, in percentage is absorbed by plants.

· How much percentage of the absorbed energy is stored in plant tissues.

· How plants and animals differ from each other in the utilization of energy.

· Analyse the way in which energy transfer and utilisation occurs, based on a food chain.

Let us examine the conclusions we arrived at.

· In the biosphere, energy transfer takes place only through the food chains.

· Each food chain can be considered as an energy chain.

· Plants utilize only 50% of the total available energy for their life processes. But each of the trophic levels utilizes 90% of their available energy for their metabolic activities. Remaining 10% of the energy alone is transferred to the next trophic level.

In relation to reduction in the number of trophic levels in a food chain, the measure of energy loss is also comparatively reduced. Now you have understood the reason why long food chains are not commonly seen in nature.