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UPSC Prelims 1994 · Environment · Nature’s Machinery
The greatest diversity of animal and plant species occurs in
- (a) temperate deciduous forests
- (b) tropical moist forests
- (c) heavily polluted rivers
- (d) deserts and savannas
Show the answer and explanation
Answer: (b) tropical moist forests
Tropical moist forests hold over half of the world’s land species on a small share of land.
The idea
A tropical moist forest is built in layers, and each layer is a different home with different light and moisture. More kinds of homes mean more kinds of species. Warmth and water all year add to this.
Emergent trees above the roof → Closed canopy → Understorey of small trees → Shrubs and saplings → Dark forest floor
Why the others are wrong
(a) Cold winters limit species in temperate forests.
(c) Pollution cuts diversity.
(d) Water shortage limits life in deserts and savannas.
Also know
These forests cover only about 6–7% of the land but are thought to hold more than half of its species. The sea’s equal is the coral reef, called the rainforest of the ocean.
🔒 Tropical moist forests = highest species diversity on land; coral reefs in the sea.