An energy pyramid provides a means of describing the feeding and energy relationships within a food chain or web.

Each step of an energy pyramid shows that some energy is stored in newly made structures of the organism which eats the preceding one.

The pyramid also shows that much of the energy is lost when one organism in a food chain eats another.

Most of this energy which is lost goes into the environment as heat energy.

While a continuous input of energy from sunlight keeps the process going, the height of energy pyramids (and therefore the length of food chains) is limited by this loss of energy.

An Energy Pyramid The picture at the left is an energy pyramid. Producer organisms represent the greatest amount of living tissue or biomass at the bottom of the pyramid.

The organisms which occupy the rest of the pyramid belong to the feeding levels indicated in each step.

On average, each feeding level only contains 10% of the energy as the one below it, with the energy that is lost mostly being transformed to heat.