Question

Which of the following correctly explains Net Primary Productivity?

• A. Rate of formation of new organic matter by consumers.
• B. Rate of production of organic matter during photosynthesis.
• C. Gross primary productivity minus respiratory losses.
• D. Rate of assimilation of food energy by consumers.

Hint:

Net primary productivity is gross primary productivity left after the producers' own respiration.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
Gross primary productivity (GPP) is the rate of production of organic matter by producers in photosynthesis.

Step 2: Net productivity
Producers use part of it in respiration (R). What remains for consumers is \(\text{NPP} = \text{GPP} - R\).

Step 3: Compare the options
Organic matter formed by consumers is secondary productivity. So NPP is gross primary productivity minus respiratory losses.

Final Answer:
Net primary productivity is gross primary productivity minus respiratory losses. \[ \boxed{\text{(C) }\text{Gross primary productivity minus respiratory losses}} \]