Question

In an ecosystem if the Net Primary Productivity (NPP) of first trophic level is 100x (kcal m^-2)yr^-1, what would be the GPP (Gross Primary Productivity) of the third trophic level of the same ecosystem?

• A. \(\frac {x}{10}\) (kcal m^-2)yr^-1
• B. \(x\) (kcal m^-2)yr^-1
• C. \(10x\) (kcal m^-2)yr^-1
• D. \(\frac {100x}{3x}\) (kcal m^-2)yr^-1

Answer 1

The Correct Option is C

The Gross Primary Productivity (GPP) at higher trophic levels (like the third trophic level) is typically much lower than that at the first trophic level due to the loss of energy between trophic levels.
Assuming a 10% energy transfer efficiency, the GPP at the third trophic level would be 10x kcal m–2 yr–1.