Question

Biologists use their observations on a small island to construct the food web shown. Their calculations indicate that the producer level has about 150,000 kilojoules of energy available. How much energy is available to the primary consumers in this food web? Explain your calculation.

Answer 1

The flow of energy from one level to another does not happen with 100% efficiency. The producers only transfer 10% of the energy they absorb from the Sun. The major chunk of the absorbed energy goes into the growth of the producers, the rest gets lost in the form of waste (shedding of leaves, reproduction, etc.) and the remaining 10% is the amount that is available to the primary consumers. So by this logic, if there is 150,000 KJ of energy available at the producer level, then, only 15,000 KJ of energy will get transferred to the primary consumers.