Question

In relation to gross primary productivity and net primary productivity of an ecosystem. Which one of the following statements is correct?

• A. Gross primary productivity and net primary productivity are one and same
• B. There is no relationship between gross primary productivity and net primary productivity
• C. Gross primary productivity is always less than net primary productivity
• D. Gross primary productivity is always more than net primary productivity

Answer 1

The correct option is D Gross primary productivity is always more than net primary productivity

The gross primary productivity (GPP) of an ecosystem is the rate of production of organic matter during photosynthesis.

Some of this organic matter is lost because of the respiration by plants. The remaining primary productivity is the net primary productivity (NPP).

Gross primary productivity (GPP) minus respiration losses (R),
is the net primary productivity (NPP) i.e., GPP – R = NPP. Hence, gross primary productivity is always more than net primary productivity.