Ecosystem consists of living and nonliving things. Living things include plants, animals, microorganisms. Nonliving things include air, water, land. The pyramids of biomass indicates the relationship between different trophic levels with regards to biomass. In lake ecosystems, there is gradual increase in biomass of organisms at successive trophic levels from the producers to the consumers. Hence, the pyramid of biomass is generally inverted in a lake ecosystem.