How does energy flow through an ecosystem?

Energy flows through an ecosystem primarily through a sequence known as trophic levels, which outline the different stages in a food chain. The flow begins with producers, typically plants or photosynthetic organisms, that convert sunlight into chemical energy through the process of photosynthesis. These producers form the base of the food chain.

As energy moves from one trophic level to the next, it typically flows from producers to primary consumers (herbivores), and then to secondary and tertiary consumers (carnivores and omnivores). At each step, energy is transferred, but not all energy is passed on; a significant portion is lost as heat due to metabolic processes. This is known as the 10% rule, which indicates that only about 10% of the energy at one trophic level is available to the next level.

This flow of energy is linear rather than circular, as it does not circulate continuously within the same organisms, nor does it move solely from consumers back to producers. Decomposers play a critical role in breaking down dead organic matter, contributing nutrients back to the soil, which supports plant growth; however, this process is a part of nutrient recycling, not energy flow. Hence, the correct understanding of energy flow through ecosystems is