Name the factors which affect the primary productivity .

Explanation

**Step-by-Step Solution:**

1. **Definition of Primary Productivity:**
- Primary productivity refers to the amount of biomass produced by autotrophs (organisms that produce their own food) at the primary level of the ecosystem. This is essentially the rate at which photosynthesis occurs in a given area.

2. **Environmental Factors:**
- Environmental conditions significantly influence primary productivity. Factors such as temperature, rainfall, and sunlight can either enhance or hinder the growth of autotrophs. For instance, excessive rainfall can lead to reduced productivity in some ecosystems, while in arid regions, rainfall can boost productivity.

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