UPSC CSE Prelims
Question 51
Which one of the following is the correct sequence of ecosystems in the order of decreasing productivity?
View correct answer and explanation
Correct answer: C
Correct Option: C
Explanation: High-productivity coastal mangroves generally exceed typical grasslands and lakes per unit area, while open oceans have very low production per unit area.
Option-wise Analysis:
A: Incorrect - Wrong: ocean productivity per unit area is lower than that of mangroves.
B: Incorrect - Wrong: it incorrectly puts oceans above grasslands and lakes.
C: Correct - Correct: mangroves → grasslands → lakes → open oceans is the intended decreasing order.
D: Incorrect - Wrong: oceans are not the most productive per unit area.
Review Note: Productivity here must be understood per unit area. Lake productivity varies considerably (oligotrophic versus eutrophic lakes), so real-world site comparisons may depart from this exam ranking.