Explanation

Factor affecting primary productivity are as follows (i) Plant species inhabiting a particular area (ii) Environmental factors Sunlight The sunlight directly regulates the primary productivity because the plants perform photosynthesis with the of sunlight. As trophic region receives maximum sunlight, so it exhibits higher productivity Temperature Temperature regulates the activity of enzyme. So, optimum temperature is required for proper functioning of enzymes Moisture Rain (humidity) is required for higher primary productivity. Deserts have the lowest primary productivity as the soil is deficient in moisture Availability of Nutrients Greater nutrients ensures the greater primary productivity Photosynthetic Efficiency Some plants have more efficiency to trap the sunlight (sugar cane), so they accumulate more primary productivity