Environmental Studies(ES)

ENVIRONMENTAL STUDIES

Lesson 12: Food chains, food webs and ecological pyramids

Pyramids of energy

Energy pyramids, otherwise known as trophic level diagrams, are used to represent the flow of energy through an ecosystem. An organism’s trophic level indicates the organism’s position in the sequence of energy transfers.

These pyramids reflect the overall nature of the ecosystem. In this pyramid, the number and weight of organisms at any trophic level depends on the rate at which food is produced but not on the amount of fixed energy at any level in a given time. Its shape is always upright since in most cases there will be a gradual decrease in the energy content at successive trophic levels from producers to various consumers.