Which of the following ecosystem has the highest gross primary productivity?

Explanation

Gross primary productivity is the total rate of photosynthesis, including the organic matter used up in respiration during the measurement period. Tropical evergreen/rainforests occur over equatorial/subequatorial regions with abundant warmth and rainfall (200-350 cm/yr) almost throughout the year. The forests are impenetrable (= jungle) with maximum diversity, e.g., 200 types of trees in one hectare, 70-80% of all insects, and 80-85% of all birds. Productivity is maximum here; it equates to 12000 kcal/m 2 /yr.