2013 · EnvironmentPrevious Year Question
Q73.
Which one of the following is the correct sequence of ecosystems in the order of decreasing productivity?
A. Oceans, lakes, grasslands, mangroves
B. Mangroves, oceans, grasslands, lakes
C. Mangroves, grasslands, lakes, oceans
D. Oceans, mangroves, lakes, grasslands
Answer

C

Explanation

Net primary productivity values: Mangroves ~2500 g/m²/yr, Grassland ~500 g/m²/yr, Lakes ~500 g/m²/yr (but slightly less than grassland), Open Ocean ~125 g/m²/yr. So the decreasing order is: Mangroves > Grasslands > Lakes > Oceans.