Question

When moving upward on an energy pyramid from one level to the next, what happens to the usable energy in an ecosystem?

Answer 1

The energy decreases by 90%

Answer 2

The right answer is “It decreases by 10%”. The amount of energy at each trophic level decreases as it moves over an ecosystem. Just 10 percent of the energy at any trophic level is relocated to the next one; the rest is lost mostly because metabolic processes like heat. Energy pyramids help to understand the trophic structure of an ecosystem: the number of consumer trophic levels that can be maintained is dependent on the magnitude and energy fertility of the producer level.