Describe with a diagram how energy flows through different trophic levels.

The energy flows from the sun which is the only continuous source of energy for the earth. Green plants trap a part of solar energy reaching the earth. If the solar energy reaching the earth is 1000 J the green plants trap only 1% i.e., 10 J of the energy as biomass. This 10 J energy as plant matter is available to the herbivore. Out of this 10 J energy 90% is lost as heat by the herbivore and only 10%, i.e., 1 J of energy is available to the carnivore, as shown below.

Fig. Energy flow and loss of energy at each trophic level



Fig. Progressive decline in amount of energy available in a food chain