Ques. 1AIPMT 2007
Which one of the following ecosystem types has the highest annual net primary productivity ?
- Temperate evergreen forest
- Temperate deciduous forest
- Tropical rain forest
- Tropical deciduous forest
Answer
(3) Tropical rain forest
Solution
As per NCERT, primary productivity depends on the plant species inhabiting a particular area and on environmental factors such as availability of nutrients and photosynthetic capacity of plants; hence it varies in different types of ecosystems.
⇒ Tropical rain forests have high temperature, high rainfall, abundant sunlight throughout the year and dense multi-layered vegetation.
∵ Photosynthesis goes on all year round, their annual net primary productivity is the highest among the given (terrestrial) ecosystems (about 2200 g m-2 yr-1).
∴ Tropical rain forest has the highest annual NPP.
Answer: (3)