Energy flow in ecosystems follows the 10% Rule: only about 10% of energy transfers from one trophic level to the next.
This means if a plant captures 1000 calories of sunlight, only about 100 calories will be available to herbivores, and just 10 calories will reach the carnivores that eat those herbivores.
The trap here is thinking energy cycles like matter.
It doesn't.
Energy dissipates as heat at each trophic step.
This loss limits the number of trophic levels and explains why top predators are rare.
Misunderstanding this can lead to overestimating an ecosystem's capacity to support organisms.
You might think more plants mean more top predators, but energy loss caps that growth.
Recognize the asymmetry: matter cycles, energy flows and depletes.
This difference underpins ecosystem structure, productivity, and the impact of human interventions.
When calculating energy transfers, always account for that 90% loss to avoid incorrect predictions about population sizes or ecosystem changes.