(b) : 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 (200−350cm∕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 80−85% of all birds. Productivity is maximum here, 12000kcal∕m2∕yr