Consider the following statements : Statement-I : The soil in tropical rain forests is rich in nutrients. Statement-II : The high temperature and moisture of tropical rain forests cause dead organic matter in the soil to decompose quickly. Which one of the following is correct in respect of the above statements?
- (a) Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I
- (b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I
- (c) Statement-I is correct but Statement-II is incorrect
- (d) Statement-I is incorrect but Statement-II is correct ✓ UPSC's answer
Why the answer is (d)
• Statement-II is correct: in the hot, humid conditions of tropical rainforests, dead leaves and organic matter decompose within weeks, releasing nutrients rapidly.
• Statement-I is incorrect: the released nutrients are immediately taken up by the dense vegetation or leached away by heavy rain, so rainforest soils (oxisols, laterites) are typically thin, acidic and nutrient-poor; the nutrients are stored in the living biomass, not the soil.
• This is why cleared rainforest land loses fertility within a few years.
• Rapid decomposition in fact explains why the soil stays poor — the opposite of Statement-I.
• Hence Statement-I is incorrect but Statement-II is correct, option (d).
Why the other options are wrong
- (a) Both Statement-I and Statement-II are correct and Statement-II is the correct explanation…
- Statement-I is wrong: rainforest soils are nutrient-poor.
- (b) Both Statement-I and Statement-II are correct and Statement-II is not the correct…
- Statement-I is wrong, so both cannot be correct.
- (c) Statement-I is correct but Statement-II is incorrect
- It is Statement-I that is incorrect and Statement-II that is correct.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2023, held on 28 May 2023. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.