Science & Technology
Biodiversity and Conservation
Biodiversity Hotspots and Megadiversity
Hotspots for CGPSC: Myers' 1,500 + 70% criteria, 36 hotspots, India's four, megadiverse countries, KBAs and the Western Ghats Gadgil-Kasturirangan debate.
Prerequisites
- Levels of Biodiversity: endemism and species diversity
- Biodiversity (Geography): biogeographic zones of India and the HIPPO threats
- Physiography of India: where the Himalaya, Western Ghats and islands lie
The Hook: Rich, but Not a Hotspot
Connect
Chhattisgarh’s forests hold tigers, elephants, wild buffalo, the hill myna, cave fish in Kanger Valley and hundreds of medicinal plants. A natural interview question follows: “Is Chhattisgarh a biodiversity hotspot?”
The answer is no, and the reason is precise. A hotspot is not just a place with many species. It must have many species found nowhere else and must have already lost most of its natural vegetation.
What exactly makes a hotspot, which ones touch India, and how else do scientists decide where to spend limited conservation effort?
Why it matters: Prelims tests the two criteria, the number 36, India’s four hotspots and their regions. Mains asks why hotspots matter and how conservation should be prioritised, often with the Western Ghats as the case study.
What Is a Biodiversity Hotspot (जैव विविधता हॉटस्पॉट)?
The idea was proposed by the British ecologist Norman Myers in 1988. Conservation International later adopted it and refined the criteria (with Myers and colleagues, around 1999–2000). A region qualifies only if it meets both conditions:
| Criterion | Threshold | What it captures |
|---|---|---|
| Irreplaceability (endemism) | At least 1,500 species of vascular plants found nowhere else (more than 0.5% of the world’s total) | The region is rich and unique |
| Threat (habitat loss) | At least 70% of the original natural vegetation lost | The region is already badly damaged |
The global picture
- 36 hotspots are recognised worldwide. The 36th, the North American Coastal Plain, was added in 2016.
- Together they cover only about 2.5% of Earth’s land surface, yet they hold more than half of the world’s plant species as endemics (and a large share of vertebrates).
- The logic is efficiency: protecting a small area saves a very large share of species that would otherwise be lost forever.
India’s Four Hotspots
| Hotspot | Indian part | Signature features |
|---|---|---|
| Himalaya | Indian Himalayan region (Sikkim, Uttarakhand, Himachal, Arunachal and others); shared with Nepal, Bhutan and neighbours | Steep altitude gradients; snow leopard, red panda; many endemic plants |
| Indo-Burma | North-East India (except parts counted in the Himalaya hotspot); shared with Myanmar, Thailand and Indochina | Among the most threatened hotspots; very high freshwater fish and bird diversity |
| Western Ghats and Sri Lanka | Western Ghats: Gujarat, Maharashtra, Goa, Karnataka, Kerala, Tamil Nadu | Very high endemism, especially amphibians; Nilgiri tahr, lion-tailed macaque |
| Sundaland | Only the Nicobar Islands | Rest is Malaysia and Indonesia; Nicobar megapode |
graph LR
I["India's 4 hotspots"] --> H["Himalaya: north"]
I --> IB["Indo-Burma: north-east"]
I --> W["Western Ghats-Sri Lanka: south-west"]
I --> S["Sundaland: Nicobar Islands only"]
Where is Chhattisgarh?
Most of Chhattisgarh lies in the Deccan Peninsula biogeographic zone, the largest of India’s ten zones. It is not part of any hotspot. Central Indian forests are rich, but their level of plant endemism does not reach the hotspot threshold. Rich + threatened is not enough without the 1,500-endemic-plant test.
The Western Ghats: a hotspot with a policy debate
- In 2012, 39 sites across the Western Ghats were inscribed together as a UNESCO World Heritage Site (natural).
- Gadgil Committee (Western Ghats Ecology Expert Panel), 2011: recommended treating the entire Western Ghats as ecologically sensitive, graded into three zones, with strong local-body participation.
- Kasturirangan Committee (High Level Working Group), 2013: narrowed the strict zone to about 37% of the region, mainly natural landscapes, citing development needs.
- The debate (strict protection vs development; top-down vs Gram Sabha-led) is a classic Mains example. Landslides in Kerala and Karnataka in recent years have revived it.
Megadiverse Countries
| Fact | Detail |
|---|---|
| What | Countries that together hold the majority of Earth’s species; identified by Conservation International (with UNEP-WCMC) |
| Number | 17 |
| India’s place | One of the 17 (about 2.4% of the world’s land, about 7–8% of recorded species) |
| Others (examples) | Brazil, Colombia, Indonesia, China, Mexico, Australia, USA, Democratic Republic of the Congo |
| Like-Minded Megadiverse Countries (LMMC) | A negotiating group formed by the Cancun Declaration (2002), focused on fair benefit sharing from genetic resources. India is a member |
Hotspot vs megadiverse
Megadiverse is about countries and richness only; there is no threat criterion. Hotspot is about regions (crossing borders) and needs endemism plus habitat loss.
Other Ways to Set Conservation Priorities
Hotspots are one priority-setting system among several. They are criticised for counting plants only for the threshold and for ignoring places that are rich but still intact.
| System | Run by | Basis |
|---|---|---|
| Biodiversity hotspots | Conservation International | Endemic plants + habitat loss |
| Global 200 ecoregions | WWF | Representative examples of every major habitat type, including freshwater and marine |
| High-Biodiversity Wilderness Areas | Conservation International | Rich and still largely intact (the opposite logic to hotspots) |
| Important Bird and Biodiversity Areas (IBAs) | BirdLife International (in India, BNHS is the partner) | Sites critical for birds |
| Key Biodiversity Areas (KBAs) | A partnership including IUCN | Sites contributing significantly to the global persistence of biodiversity; IBAs are a subset |
| Ramsar sites | Ramsar Convention (1971) | Wetlands of international importance |
Analysis for Mains: Strengths and Limits of the Hotspot Approach
Strengths
- Efficient: a small fraction of land, a very large share of irreplaceable species.
- Clear, measurable criteria that donors and governments can use.
- Focus on urgency: hotspots are, by definition, places where loss has already happened.
Limits
- Plant-based: the threshold counts only vascular plants; animals, fungi and microbes are not in the test.
- Ignores intact areas: a rich forest that is still intact (much of central India’s forest belt, for example) gets no hotspot attention until it is degraded.
- Ignores ecosystem services and people: a region may be vital for water, livelihoods or carbon without being a hotspot.
- Political boundaries: hotspots cross borders, but conservation laws are national.
For India: combine hotspot priorities with landscape conservation (tiger and elephant corridors in central India), community-based protection (BMCs, sacred groves, FRA community rights), and the 30% area target under the Kunming-Montreal framework (see Conservation Laws and Institutions).
Memory Tricks
Criteria: '1500 and 70'
“Fifteen hundred rich, seventy percent ruined.” At least 1,500 endemic plants and at least 70% vegetation lost. Both are required.
India's hotspots: 'HIWS'
Himalaya, Indo-Burma, Western Ghats–Sri Lanka, Sundaland (Nicobar). Say it as “hiss”.
Western Ghats committees in order
“G before K, broad before narrow”: Gadgil (2011, entire Ghats sensitive) → Kasturirangan (2013, about 37%).
Don’t Confuse
| This | vs | That |
|---|---|---|
| Hotspot: region, endemism + 70% loss, 36 worldwide | Megadiverse country: country, richness only, 17 | |
| Hotspot: rich and threatened | High-Biodiversity Wilderness Area: rich and intact | |
| Sundaland in India: Nicobar Islands | Indo-Burma in India: North-East | |
| Gadgil (WGEEP), 2011: whole Ghats sensitive | Kasturirangan (HLWG), 2013: about 37% | |
| Western Ghats WHS (2012): UNESCO heritage listing | Western Ghats hotspot: Conservation International priority region (not a legal status) | |
| Deccan Peninsula: biogeographic zone (includes Chhattisgarh) | Hotspot: Chhattisgarh is in none |
Common Mistakes
Trap 1: India has three hotspots
India has four. Sundaland is counted through the Nicobar Islands. Options often omit it.
Trap 2: either criterion is enough
A hotspot must meet both criteria. High endemism alone or heavy habitat loss alone does not qualify.
Trap 3: Andaman in Sundaland
India’s share of Sundaland is the Nicobar group. The Andaman Islands are usually mapped with the Indo-Burma hotspot.
Trap 4: hotspots are legally protected
“Hotspot” is a scientific priority label by an NGO (Conservation International). It gives no legal protection by itself. Legal protection comes from national laws such as the WPA.
Practice
All questions below are original practice questions written in CGPSC style. They are not previous-year questions.
Level 1: Foundation
- The concept of biodiversity hotspots was proposed by ________ in ________.
- There are ________ biodiversity hotspots in the world, of which ________ include part of India.
- India’s share of the Sundaland hotspot is the ________ Islands.
Answers
- Norman Myers; 1988.
- 36; 4.
- Nicobar.
Level 2: Prelims MCQs
Q1. Consider the following statements about biodiversity hotspots:
- A region qualifies as a hotspot if it has either 1,500 endemic vascular plant species or has lost 70% of its natural vegetation.
- Hotspots together cover about 2.5% of Earth’s land surface.
- Being declared a hotspot gives a region legal protection under the Convention on Biological Diversity.
Which of the statements given above is/are correct?
- (a) 1 and 2 only
- (b) 2 only
- (c) 2 and 3 only
- (d) 1, 2 and 3
Answer and explanation
(b) 2 only. Both criteria must be met, not either one (statement 1 is wrong). The hotspot label comes from Conservation International and has no legal force under the CBD or any other treaty (statement 3 is wrong). Statement 2 is correct.
Q2. Match List I (Hotspot) with List II (Indian region):
| List I | List II |
|---|---|
| A. Indo-Burma | 1. Nicobar Islands |
| B. Sundaland | 2. Kerala, Karnataka, Goa |
| C. Western Ghats and Sri Lanka | 3. North-Eastern states |
| D. Himalaya | 4. Sikkim, Uttarakhand, Himachal Pradesh |
- (a) A-1, B-3, C-2, D-4
- (b) A-3, B-1, C-2, D-4
- (c) A-3, B-1, C-4, D-2
- (d) A-3, B-2, C-1, D-4
Answer and explanation
(b) A-3, B-1, C-2, D-4. Indo-Burma covers the North-East; Sundaland enters India only through the Nicobar Islands; the Western Ghats run through Kerala, Karnataka, Goa, Maharashtra, Tamil Nadu and Gujarat; the Himalaya hotspot covers the Indian Himalayan states.
Q3. Which one of the following is the main reason Chhattisgarh is NOT counted in any biodiversity hotspot?
- (a) It has very little forest cover
- (b) Its level of endemic plant species does not meet the hotspot threshold
- (c) It has lost less than 10% of its forests
- (d) It does not lie in any biogeographic zone
Answer and explanation
(b). Chhattisgarh has about 41% forest cover (ISFR 2023) and lies in the Deccan Peninsula zone, so (a) and (d) are wrong. The decisive test it fails is endemism: central Indian forests do not hold 1,500 endemic vascular plants. Option (c) states a figure that is not established and is not the defining reason.
Q4. Which of the following committees recommended that the entire Western Ghats be treated as ecologically sensitive?
- (a) Kasturirangan Committee
- (b) Madhav Gadgil Committee
- (c) T.S.R. Subramanian Committee
- (d) M.S. Swaminathan Committee
Answer and explanation
(b) Madhav Gadgil Committee (Western Ghats Ecology Expert Panel, 2011). The Kasturirangan High Level Working Group (2013) narrowed the strict zone to about 37% of the region. The Subramanian committee (2014) reviewed environmental laws in general.
Q5. “Megadiverse countries” differ from “biodiversity hotspots” because megadiverse status:
- (a) requires at least 70% habitat loss
- (b) is based on species richness of a country, with no threat criterion
- (c) is granted by UNESCO
- (d) applies only to island nations
Answer and explanation
(b). The 17 megadiverse countries (identified by Conservation International) are chosen for their share of global species. There is no habitat-loss test. India is one of them.
Level 3: Mains Answer Writing
Q1. (60 words) What is a biodiversity hotspot? Why is Chhattisgarh not part of one?
Model answer outline
- Definition: region with at least 1,500 endemic vascular plants (more than 0.5% of world total) and at least 70% of original vegetation lost (Myers 1988; Conservation International). 36 worldwide; 4 in India.
- Chhattisgarh: rich forests in the Deccan Peninsula zone, but plant endemism below the threshold, so it is in no hotspot.
- One line: hotspot status is a priority label, not a measure of overall value.
Q2. (150–200 words) Critically evaluate the hotspot approach to biodiversity conservation, with reference to India.
Model answer outline
- Intro: Myers (1988) proposed concentrating effort where endemism is highest and threat greatest. 36 hotspots cover about 2.5% of land but hold over half of plant species as endemics.
- Strengths: efficiency; clear criteria; urgency; India’s four hotspots (Himalaya, Indo-Burma, Western Ghats–Sri Lanka, Sundaland) attract research and funding.
- Limits: plant-only threshold; ignores intact but rich areas like central India’s sal forests; ignores ecosystem services and livelihoods; no legal force; cross-border regions face national laws.
- Indian example: Western Ghats: WHS (2012), yet the Gadgil (2011) vs Kasturirangan (2013) debate shows that a label does not settle development conflicts.
- Way forward: combine hotspots with KBAs, landscape corridors, community conservation (BMCs, sacred groves, FRA rights) and the 30% area target of the Kunming-Montreal framework.
- Conclusion: Hotspots are a useful compass, not a complete map.
Quick Revision Table
| Fact | Detail |
|---|---|
| Proposed by | Norman Myers, 1988; adopted by Conservation International |
| Criteria | ≥1,500 endemic vascular plants (>0.5% of world) and ≥70% original vegetation lost |
| Number | 36 worldwide (36th: North American Coastal Plain, 2016) |
| Coverage | About 2.5% of land; more than half of plant species as endemics |
| India’s four | Himalaya, Indo-Burma, Western Ghats–Sri Lanka, Sundaland (Nicobar) |
| Chhattisgarh | In no hotspot; Deccan Peninsula zone |
| Megadiverse countries | 17 (India included); LMMC from Cancun Declaration, 2002 |
| Western Ghats | UNESCO WHS 2012 (39 sites); Gadgil 2011; Kasturirangan 2013 (about 37%) |
| Other priority systems | WWF Global 200; HBWA; IBAs (BirdLife/BNHS); KBAs |
Key Takeaways
Key Takeaways
- A hotspot needs both high endemism (1,500 plants) and high threat (70% loss).
- 36 hotspots worldwide; 4 touch India; Sundaland enters India only via the Nicobar Islands.
- Chhattisgarh is in no hotspot, because of endemism, not because it lacks forest.
- Megadiverse (17 countries) measures richness only; India is one.
- Hotspots are a priority label, not a legal status; good policy combines them with landscapes, KBAs and community conservation.
What’s Next
- In-situ Conservation: India’s Protected-Area Network: how India protects habitats on the ground
- Environmental Conventions: CBD, Ramsar and CITES
- Physiography of India: the landforms behind the hotspots
- Forests and Wildlife of Chhattisgarh: rich forests outside the hotspots
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