The following scenario is the basis for questions 1 through 5. Assume you measured the energy levels in a plant-caterpillar ecosystem (g C m-2 yr-1). Net primary productivity (NPP) was assessed to be 600 g C m-2 yr-1, whereas gross primary productivity (GPP) was measured to be 1500 g C m-2 yr-1. You estimate that the caterpillars absorb 80 g C m-2 yr-1 of the NPP (the remainder being left unfinished). Caterpillars absorb 55 g C m-2 yr-1 of the 80 g C m-2 yr-1 they ingest (regurgitating or excreting the rest). Ultimately, the caterpillars use 20 g C m-2 yr-1 of the absorbed quantity for development and reproduction.
What is the consumption efficiency of the caterpillars?
A. 80/1500 = 0.0533 = 5.33%
B. 80/600 = 0.1333 = 13.33%
C. 55/20 = 2.75 = 275%
D. 55/80 = 0.6875 = 68.75%