In a forest food web there are three trophic levels: producers, herbivores and carnivores. If the total biomass of producers is $2000{\text{gm}}^{-2}$ and the average ecological efficiency between successive levels is 10%, calculate the biomass of carnivores per square metre.

Step-by-step solution

1. First transfer: biomass to herbivores = $2000\times 0.10=200{\text{gm}}^{-2}$.
2. Second transfer: biomass to carnivores = $200\times 0.10=20{\text{gm}}^{-2}$.
3. Thus the carnivore biomass is $20{\text{gm}}^{-2}$.

Concept tested: Biomass transfer efficiency

Published 4 October 2026 · How this solution was prepared and checked