Question

Give a brief description of the factors that affect primary productivity.

Answer 1

Factors that affect primary productivity are as follows:

1. It depends on the plant species inhabiting a particular area.
2. It depends upon environmental factors such as light, temperature, water, precipitation, etc.
3. It depends upon the availability of nutrients.
4. It also depends upon the photosynthetic capacity of plants. The greater the photosynthetic activity, the higher will be the primary productivity.

Answer 2

1. Solar radiation: The tropics have the most available light. Poles receive little light. As a result, photosynthesis is at its peak, and net primary production (NPP) in the tropics exceeds(20 t ha^-1 year^-1), compared to 8 t ha^-1 year^-1 in temperate forests.
2. Temperature: Because of the cold environment, temperate forests produce less (8 t ha^-1 year^-1) than tropical rainforests (20 t ha^-1 year^-1).
3. Moisture: Rainfall and humidity improve ecological production.
4. Nutrients: Nutrients are necessary for producer growth. Desert soils are lacking in nutrients and, thus, less productive.
5. Photosynthetic efficiency of producers: C₄ plants are more productive than C₃ plants.