Definition - What does Biomass Pyramid mean?
A biomass pyramid is a graphical representation of the relative biomasses of different ecosystems in a food chain, from primary producers to tertiary (or beyond) consumers, that is represented in a pyramid shape. A biomass pyramid demonstrates how biomass decreases as we move further up the food chain. Biomass is the collective weight of an ecosystem or a section of the food chain.
Safeopedia explains Biomass Pyramid
Just as with an energy pyramid, where we see that energy is lost to entropy as one species consumes another and we move up the food chain, we also see that the collective mass of matter which makes up individual sections of a food chain decreases as we move up a food chain, as is represented in the biomass pyramid.