Question

What is primary productivity? Discuss in brief the factors affecting the primary productivity.

Hint:

Recall GPP vs NPP, and the light/temperature/water/nutrient/CO2 factors governing photosynthesis rate.

Answer 1

Step 1: Definition:
Primary productivity is the amount of biomass or organic matter produced by autotrophs (mainly green plants) per unit area over a given period of time through photosynthesis; Gross Primary Productivity (GPP) is the total rate of production, while Net Primary Productivity (NPP) is GPP minus the biomass lost to the plant's own respiration.

Step 2: Environmental Factors:
Primary productivity depends on the availability of sunlight (light intensity and duration), temperature, and water availability (rainfall), all of which regulate the rate of photosynthesis.