What does a biomass pyramid illustrate?

A biomass pyramid illustrates the total mass of organisms at each trophic level within an ecosystem. This representation allows us to visualize how the biomass—the total mass of living organisms—changes as one moves up the food chain, from primary producers to top predators.

In a typical biomass pyramid, the base consists of producers (like plants), which have the highest biomass. As one moves up to herbivores and then to carnivores, the biomass generally decreases due to energy loss at each trophic level—approximately 90% of energy is lost primarily through metabolic processes and heat. This concept reflects the efficiency of energy transfer and how the biomass can serve as a visual measure of the health and productivity of an ecosystem.

While it may seem that measuring energy transfer efficiency is related, that would be more representative of an energy pyramid rather than a biomass one. Biomass specifically focuses on the mass of living material, distinguishing it from other ecological pyramids that emphasize energy or species diversity.