How much energy is typically transferred between each trophic level in an ecosystem?

The concept of energy transfer in an ecosystem is often represented by the 10% rule, which states that only about 10% of the energy available at one trophic level is passed on to the next level. This rule helps explain the energy dynamics within food chains, where energy diminishes as it moves up from producers (like plants) to primary consumers (herbivores) and then to secondary consumers (carnivores).

This limited transfer of energy occurs due to several factors. Firstly, energy is lost through metabolic processes—organisms use energy for growth, reproduction, and maintenance, which means it's not all passed on when one organism is consumed by another. Additionally, energy is released as heat during metabolic activities, further decreasing the amount available for the next trophic level.

By understanding the 10% energy transfer concept, one can grasp why higher trophic levels (like apex predators) generally have fewer individuals and require larger territories, as there is less energy available to support them compared to those lower in the food chain. This principle is foundational to studying ecosystems and food webs, emphasizing the inefficiencies in energy transfer.