UPSC Prelims 2011 Q20: Environment & Ecology – Biodiversity & Conservation
Three of the following criteria have contributed to the recognition of Western Ghats - Sri
Lanka and Indo - Burma regions as hotspots of biodiversity:
1. Species richness
2. Vegetation density
3. Endemism
4. Ethno - botanical importance
5. Threat perception
6. Adaptation of flora and fauna to warm and humid conditions Which three of the above are
correct criteria in this context?
- (a) 1, 2 and 6
- (b) 2, 4 and 6
- (c) 1, 3 and 5
- (d) 3, 4 and 6
Answer: (c) 1, 3 and 5
Explanation
Why Western Ghats-Sri Lanka and Indo-Burma are 'biodiversity hotspots'
A region becomes a recognised biodiversity hotspot (concept by Norman Myers) when it meets specific scientific criteria, not vegetation density or adaptation traits.
| Criterion | Used for hotspot status? | Reason |
|---|---|---|
| 1. Species richness | Yes | A hotspot must hold a large number of species |
| 2. Vegetation density | No | Density of plant cover is not a defining criterion |
| 3. Endemism | Yes | Must have 1,500+ endemic plant species found nowhere else |
| 4. Ethno-botanical importance | No | Traditional plant-use knowledge is not a hotspot criterion |
| 5. Threat perception | Yes | Must have lost over 70% of its original habitat (under serious threat) |
| 6. Adaptation to warm, humid conditions | No | Climate adaptation is not a defining criterion |
Myers' two hotspot criteria, combined:
| Criterion | Threshold |
|---|---|
| Endemism | At least 1,500 endemic vascular plant species |
| Threat | Lost ≥70% of its original (primary) vegetation |
Answer: (c) 1, 3 and 5.
Why each option is right or wrong
- (a) Incorrect. Vegetation density and climate adaptation are not hotspot criteria; endemism and threat are missing.
- (b) Incorrect. Vegetation density and ethno-botanical importance are not the defining criteria.
- (c) CORRECT. Species richness, endemism and threat perception are the real criteria for hotspot status.
- (d) Incorrect. Endemism alone from this set is right; density-adaptation and ethno-botanical importance are not criteria.
Key point
Biodiversity hotspot criteria (Myers): high species richness, high endemism (≥1,500 endemic plants), and severe threat (≥70% habitat loss). Not vegetation density, ethno-botany, or climate adaptation.
Remember
Hotspot = species richness + endemism + threat (habitat loss ≥70%).
Common mistakes
- Treating vegetation density as a proxy for biodiversity, which it is not.
- Adding ethno-botanical importance, a cultural factor, to a strictly ecological criterion list.
- Forgetting that threat/habitat loss is as important as richness and endemism.
Exam tip
Hotspot criteria are always: richness + endemism + threat. Anything about culture, density or climate adaptation is a distractor.
Sources
- Conservation International — Biodiversity Hotspots definition and criteria
- Norman Myers et al. (2000) — Biodiversity hotspots for conservation priorities, Nature