UPSC Prelims 2011 question on Rain Forest Slow Regeneration

Analysis

Tropical rainforests have dense vegetation, but their soils are generally poor in nutrients. Most nutrients are stored in living biomass, not in the soil.

1. The soil of rain forest is deficient in nutrients — Correct

In rainforests, heat and humidity cause rapid decomposition of organic matter.

Plants quickly absorb released nutrients, while heavy rainfall leaches the remaining nutrients from the soil. So, once the forest is cleared, the soil cannot support quick regeneration.

2. Propagules of trees in rain forests are poor in viability — Incorrect

Seed viability may vary among species, but it is not the main reason for slow regeneration after clearing.

The major limiting factor is nutrient-poor soil.

3. Rain forest species are slow-growing — Incorrect

Many rainforest pioneer species can grow quickly when light and nutrients are available.

Slow regeneration mainly occurs because clearing removes the nutrient-rich biomass and exposes poor soil.

4. Exotic species invade the fertile soil of rain forests — Incorrect

Invasion by exotic species can affect ecosystems, but rainforest soil is not generally fertile.

The main issue is nutrient deficiency and leaching.