Figure 57.9 Pyramid Diagrams Show Energy Flow and Biomass in Food Webs Pyramid diagrams allow ecologists to compare patterns of energy flow and biomass in food webs. (A) Forest ecosystems have lower trophic efficiency than (B) grasslands because much of the biomass in forests is wood, and thus unavailable to most primary consumers. (C) In open oceans, the rapid rate of primary production can support a larger biomass of primary consumers.