Energy loss from food chains

In transfers from one level to the next in a food chain, 90% of energy is lost as

• heat
• movement
• undigested materials.

10% is used for growth.

Pyramids

Pyramid of numbers – a graphic which displays the numbers of each organism at each level of the food chain.

Count up all the plants (producers) in an area, then herbivores (primary consumers) then the secondary consumers and so on. For each level draw a bar to scale, and you mostly get a pyramid. But not always.

Pyramid of energy – a graphic which displays the total energy of all organisms at each level of the food chain.

A pyramid of energy is always a pyramid shape – no exceptions. But it has a major drawback. It is difficult to measure, calculate, or even estimate the amount of energy which flows through each level of an ecosystem.

Topic Summary