In a temperate forest, net primary production is $8000{\text{kJ m}}^{-2}{\text{d}}^{-1}$. The energy transfer efficiency from producers to primary consumers is 15\% and from primary consumers to secondary consumers is 10\%. Calculate the energy available to secondary consumers per square metre per day.

Step-by-step solution

1. Convert percentages to decimals: 15\% = 0.15 and 10\% = 0.10.
2. Energy transferred to primary consumers = $8000\times 0.15=1200{\text{kJ m}}^{-2}{\text{d}}^{-1}$.
3. Energy transferred to secondary consumers = $1200\times 0.10=120{\text{kJ m}}^{-2}{\text{d}}^{-1}$.
4. Thus secondary consumers receive $120{\text{kJ m}}^{-2}{\text{d}}^{-1}$.

Concept tested: energy transfer efficiency

Published 21 September 2026 · How this solution was prepared and checked