Question

How is ecological efficiency calculated?

Answer 1

Formula:

\[\text{Ecological efficiency} = \frac{\text{Energy in biomass production at a trophic level}}{\text{Energy in biomass production at the previous trophic level}} \times 100\]

Other related efficiencies:

• Photosynthetic efficiency: \[\frac{\text{GPP}}{\text{Incident solar radiation}} \times 100\]
• Net production efficiency: \[\frac{\text{NPP}}{\text{GPP}} \times 100\]
• Assimilation efficiency: \[\frac{\text{Food energy assimilated}}{\text{Food energy ingested}} \times 100\]

Calculation example (from the 10% law example):

Given: Clover = 10000 kcal, Mice = 1000 kcal

\[\text{Ecological efficiency} = \frac{1000}{10000} \times 100 = 10%\]

Skunks = 100 kcal, so \[\frac{100}{1000} \times 100 = 10%\]