What is the 10% rule and how does that relate to the energy pyramid?
The 10% rule states that only about 10% of energy stored in one trophic level is transferred to organisms in the next trophic level when they are consumed. This concept is related to the energy pyramid, a graphical representation of energy flow through multiple levels (trophic levels) in an ecosystem. The energy pyramid consists of primary producers at the bottom (the first trophic level), followed by consumers at various trophic levels above them (herbivores, primary carnivores, secondary carnivores, etc.).
In the context of the energy pyramid, the 10% rule illustrates that as energy moves up the trophic levels, only a small portion is passed on, while the majority is lost as heat or used up for metabolic activities. This results in an overall decrease in the amount of available energy at each higher trophic level. Consequently, energy pyramids have a smaller biomass and number of organisms as we go up through the trophic levels. This also helps explain why there are fewer top predators in an ecosystem compared to primary producers or primary consumers.