Prelims 2011 · archive
EasyIf 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
- NASA Earth Observatory – Tropical Deforestation ↗ “Nearly all the nutrient content of a tropical forest is in the living plants and the decomposing litter on the forest floor.”
- FAO – Local technical knowledge, shifting cultivation and natural forest management ↗ “Since tropical soils are generally poor in nutrients, the tropical forest ecosystem depends on a self-contained, almost closed, nutrient cycle.”
Question: UPSC Civil Services (Preliminary) 2011, General Studies paper. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·