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UPSC CSE Prelims 2011 · GS Paper I · Ecology & ecosystems

If a tropical rainforest is removed, it does not regenerate quickly as compared to a tropical…

UPSC Civil Services (Preliminary) Examination 2011, General Studies Paper I — Ecology & ecosystems.

Prelims 2011

Ecology & ecosystems Easy

If a tropical rainforest is removed, it does not regenerate quickly as compared to a tropical deciduous forest. This is because

Answer & explanation

Answer: (a) The soil of rainforest is deficient in nutrients

Rainforest soils are thin and poor in nutrients because heavy rain and heat wash minerals out. Almost all the nutrients sit in the living plants and leaf litter. When the trees are removed, that store is lost, so the forest cannot rebuild quickly.

  • ✓ (a) Tropical soils are naturally nutrient-poor. The forest survives on a nearly closed cycle in which nutrients are held in the plants and decomposing litter. Clearing or burning the vegetation removes this nutrient reservoir, and erosion and leaching of the exposed soil worsen the loss.
  • ✗ (b) Slow regrowth is not caused by poor seed viability. The difficulty lies in the nutrient-depleted soil left after clearing, not in the trees' propagules.
  • ✗ (c) The species' growth rate is not the cause. Recovery is blocked because the nutrient stock is removed with the vegetation, leaving infertile soil behind.
  • ✗ (d) Rainforest soil is not fertile. Its nutrients are held in the living plants and litter, not in the soil, so the premise of this option is wrong.

Remember · Rainforest nutrients are locked in living biomass and litter, not in the leached soil. Remove the trees and the nutrient store goes with them.

Sources

Question: UPSC Civil Services (Preliminary) 2011, General Studies Paper I. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·

Cite this question: UPSC CSE Prelims 2011 — minimalistias.com/pyqs/prelims/2011/q56

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