CAPF AC 2023 Q38: Environment & Ecology – Biodiversity & Conservation
- (a) Temperate forests
- (b) Deserts and Savannas
- (c) Arctic and Alpine systems
- (d) Tropical moist forests
Answer: (d) Tropical moist forests
Explanation
Where life is richest
How to think: biodiversity rises as you move from the poles to the equator.
Warmth, steady rain and sunlight all year allow many species to live side by side.
The richest of all is the tropical moist (rain) forest.
| Habitat | Species richness |
|---|---|
| Tropical moist forests | Highest |
| Temperate forests | Moderate |
| Deserts and savannas | Low to moderate |
| Arctic and alpine systems | Lowest |
Examples: the Amazon rainforest holds over a million species of insects alone; in India the Western Ghats and the north-east show the same pattern.
Bank key corrected: the stored key was (b) Deserts and Savannas, which is wrong.
Answer: (d) Tropical moist forests.
Why each option is right or wrong
- (a) Incorrect. Temperate forests have fewer species than the tropics.
- (b) Incorrect. Deserts and savannas have harsh or seasonal conditions and low diversity.
- (c) Incorrect. Arctic and alpine systems are cold and have the fewest species.
- (d) CORRECT. Tropical moist forests hold the greatest diversity of animals and plants.
Key point
Latitudinal gradient: species richness falls from equator to poles. Tropical rain forests: about 7% of land, over half of all species. Amazon: about 40,000 plant species, 3,000 fishes. India: a megadiverse country with four hotspots.
Remember
Diversity peaks at the equator: tropical rain forest.
Common mistakes
- Choosing the biome with the biggest area instead of the one with the most species.
- Thinking a harsh habitat has more species because they are 'adapted'.
- Confusing savanna (grass with scattered trees) with a rain forest.
Exam tip
Educated guess: warm, wet and sunny all year is the best recipe for life, which points to tropical moist forest. Cold arctic and dry desert are obviously poorer.
Sources
- NCERT Class XII Biology — Biodiversity and Conservation, Chapter 15 (patterns of biodiversity: latitudinal gradients)
- Eugene P. Odum and Gary W. Barrett, Fundamentals of Ecology — latitudinal gradients in species diversity