Definition and Criteria
The concept of biodiversity hotspots was developed to identify and prioritize regions around the world that are exceptionally rich in biodiversity and are under severe threat of habitat loss. Focusing conservation efforts on these hotspots is considered a cost-effective strategy to protect a large proportion of global biodiversity.
The concept was first formally proposed by British ecologist Norman Myers in 1988 and 1990, and subsequently refined and adopted by Conservation International (CI).
To qualify as a biodiversity hotspot, a region must meet two strict criteria:
High Species Endemism
It must contain at least 1,500 species of vascular plants (> 0.5% of the world's total) as endemics. Endemic species are those found exclusively in that specific geographic area and nowhere else. Plants are chosen as a key indicator because they form the base of most terrestrial ecosystems.
High Degree of Threat
It must have lost at least 70% of its original natural vegetation/primary habitat. This criterion emphasizes the urgency for conservation action.
≥ 1,500 Endemic Vascular Plant Species
(> 0.5% of world's total)
≥ 70% Habitat Loss
(Original natural vegetation)
Biodiversity Hotspot
Rationale behind the Hotspot Concept
Prioritization
Limited resources (funding, personnel, political will) are channeled to areas with maximum impact for saving unique species.
Efficiency
Focusing on small areas harboring disproportionately large biodiversity enhances conservation effectiveness.
Irreplaceability
Endemic species are found nowhere else; their habitat loss means global extinction.
Vulnerability
The 70% habitat loss criterion highlights the extreme vulnerability and urgent need for action.
Global Biodiversity Hotspots
Initially, Myers identified 10 tropical forest hotspots in 1988, later expanding to 18 in 1990. Conservation International undertook a comprehensive global review and update. As of the latest updates (e.g., Mittermeier et al., 2004, and subsequent revisions), there are 36 recognized biodiversity hotspots globally.
Astounding Concentration of Life:
These 36 hotspots collectively cover only about 2.4% of the Earth's land surface but support more than half of the world's plant species as endemics (at least 150,000 species) and nearly 43% of bird, mammal, reptile, and amphibian species as endemics. They also harbor a significant proportion of threatened species.
Hotspots: Small Area, Big Impact
Illustrative representation of hotspot significance.
Most hotspots are located in tropical and subtropical regions, often in areas with complex topography (mountains, islands) which promotes speciation and endemism.
Examples of Global Hotspots (besides those in India):
Madagascar & Indian Ocean Islands
Unique flora and fauna, including lemurs.
Tropical Andes
World's richest and most diverse hotspot.
Mesoamerica
Rich in species from North and South America.
Caribbean Islands
Exceptional plant and vertebrate endemism.
Atlantic Forest (Brazil)
Highly threatened, rich in endemics.
Cape Floristic Region (South Africa)
Extraordinary concentration of plant species.
Biodiversity Hotspots in India
India is home to four of the 36 global biodiversity hotspots, showcasing its immense ecological richness and conservation importance.
The Himalayas (Eastern Himalayas)
Region (Globally): Nepal, Bhutan, China, Myanmar, and Indian states (Arunachal Pradesh, Sikkim, etc.).
Biodiversity Significance:
- Dramatic altitudinal gradients, diverse ecosystems.
- Rich plant diversity (c. 10,000 species, 3,160 endemic), orchids, rhododendrons.
- Fauna: Snow Leopard, Red Panda, Takin, Golden Langur.
- High bird, amphibian, and reptilian diversity.
Threats:
- Deforestation (agriculture, timber), infrastructure, overgrazing, poaching, climate change.
The Western Ghats and Sri Lanka
Region: Western Ghats mountain range (peninsular India) and Sri Lanka.
Biodiversity Significance (Western Ghats):
- High endemism in plants (1,800+), amphibians (c. 80% endemic, e.g., Purple Frog), reptiles, fish.
- Diverse forests: evergreen rainforests, shola forests.
- Fauna: Asian Elephant, Tiger, Lion-tailed Macaque (endemic), Nilgiri Tahr (endemic).
- Source of major peninsular rivers.
Threats:
- Habitat loss (agriculture, mining, dams), poaching, human-wildlife conflict, invasive species.
Indo-Burma Region (parts of North-East India)
Region (Globally): Eastern Bangladesh, NE India (Mizoram, Manipur, etc.), SE Asia.
Biodiversity Significance (Indian Portion):
- Diverse forests, grasslands, wetlands, bamboo brakes.
- Rich flora (orchids, bamboos), important faunal diversity (Hoolock Gibbon, Clouded Leopard).
- High diversity of freshwater fish and birds.
- Considered a large remaining wilderness area in tropical Asia.
Threats:
- Deforestation, infrastructure, hunting, illegal wildlife trade, wetland drainage.
Sundaland (Nicobar Islands)
Region (Globally): SE Asia (Indonesia, Malaysia, etc.) and India's Nicobar Islands.
Biodiversity Significance (Nicobar Islands):
- Tropical rainforests, mangroves, coastal ecosystems.
- High endemism in plants, birds (Nicobar Megapode), reptiles, mammals (Nicobar Tree Shrew).
- Important marine biodiversity (coral reefs, seagrass beds).
Threats:
- Habitat loss (agriculture), tourism impacts, over-exploitation of marine resources, natural disasters, climate change.
"Hottest Hotspots"
Within the global hotspots, some are considered "hottest hotspots" – those that are most severely threatened and have the highest irreplaceability (highest number of endemics). The Western Ghats & Sri Lanka and the Indo-Burma region are often cited in this critical category, demanding urgent and intensive conservation focus.
Significance for Conservation Planning
Targeted Action
Focuses limited resources on areas of highest global biodiversity significance and threat.
Flagship for Conservation
Raises public awareness and garners support for conservation efforts.
International Cooperation
Necessitates collaboration for transboundary hotspots.
Guiding Investment
Influences funding decisions by international donors and NGOs.
Criticisms and Limitations
May neglect large wilderness areas with intact processes but lower species richness (e.g., Boreal forests, "Coldspots," HBWAs) or functionally important ecosystems not rich in species.
The 1,500 endemic plant species criterion may not always align with faunal endemism or overall ecosystem diversity hotspots.
The 70% habitat loss criterion is somewhat arbitrary; regions with slightly less loss but high endemism might be overlooked.
Hotspots are large; action needs finer scaling. Over-emphasis might lead to underfunding other important areas.
Can conflict with local livelihoods if not participatory. Data deficiencies can affect designation precision.
Complementary Conservation Strategies
While valuable, the hotspot approach should be part of a broader strategy that includes:
- Protecting High-Biodiversity Wilderness Areas (HBWAs).
- Ecosystem-based management approaches.
- Species-specific conservation programs (e.g., flagship/keystone species).
- Conserving genetic diversity (gene banks, wild crop relatives).
- Addressing underlying drivers of biodiversity loss (consumption, poverty).
- Mainstreaming biodiversity into development sectors.
Historical Context of Hotspot Recognition
Norman Myers' Initial Proposal
Publishes first article in "The Environmentalist" identifying 10 tropical forest hotspots, including Western Ghats and Eastern Himalayas.
Expansion by Myers
Expands the list to 18 hotspots in a subsequent article.
Conservation International (CI) Review
CI adopts and refines the concept, conducting a global review that identifies 25 hotspots.
Further Updates & Expansion
Mittermeier et al. (2004) and subsequent revisions expand the list to the current 36 hotspots, formalizing the four that include parts of India. This recognition boosts conservation focus.
Case Study: Conservation in the Western Ghats
Recognition & Significance
Globally recognized for exceptional biodiversity and high threat. It demonstrates the complex interplay of ecological importance, socio-economic factors, policy, and ongoing conservation challenges.
Conservation Measures
- Protected Area Network: National Parks (Silent Valley, Periyar), Wildlife Sanctuaries, Biosphere Reserves (Nilgiri, Agasthyamalai).
- Legal Framework: Wildlife (Protection) Act 1972, Forest (Conservation) Act 1980, Biological Diversity Act 2002.
- Species-Specific Projects: Project Tiger, Project Elephant.
- Eco-Sensitive Zones (ESZs): Around protected areas to regulate activities.
- Expert Committees: Gadgil & Kasturirangan Committees (recommendations on zonation, contentious implementation).
- Community-based Conservation: Efforts involving local communities.
- Research & Monitoring: By WII, ATREE, universities.
Challenges
Balancing conservation with development (mining, dams), human-wildlife conflict, effective PA management, invasive species, climate change.
UPSC Civil Services Exam Relevance
Prelims Focus
- Concept of biodiversity hotspots.
- Criteria for designation (endemic plants %, habitat loss %).
- Names and general locations of global hotspots.
- Specifics of the 4 Indian hotspots (features, endemics, threats).
- Organizations involved (e.g., Conservation International).
Mains (GS Paper III - Environment)
- "What are biodiversity hotspots? Identify India's hotspots & threats." (Probable question)
- "Critically evaluate the hotspot approach for global conservation."
- Mentioning hotspots in answers on India's biodiversity conservation.
- Linkages to Gadgil/Kasturirangan reports (Western Ghats).
Related Previous Year Questions (Illustrative)
UPSC Prelims Style Question:
"Biodiversity hotspots are located only in tropical regions. India has four biodiversity hotspots i.e., Eastern Himalayas, Western Himalayas, Western Ghats and Andaman and Nicobar Islands. Which of the statements given above is/are correct?"
(Note: This tests factual accuracy. Statement 1 is incorrect - e.g., Mediterranean Basin. Statement 2 is inaccurately phrased regarding Indian hotspots - Western Himalayas is not a hotspot, Sundaland includes Nicobar, Indo-Burma includes parts of NE.)
UPSC Prelims 2010 (Variation):
"Consider the following regions: 1. Eastern Himalayas, 2. Eastern Mediterranean region, 3. North-western Australia. Which of the above is/are Biodiversity Hotspot(s)?"
(a) 1 only (b) 1 and 2 only (c) 2 and 3 only (d) 1, 2 and 3
Answer: (b)
UPSC Mains 2018 (GS Paper III - Related):
"How does biodiversity vary in India? How is the Biological Diversity Act, 2002 helpful in conservation of flora and fauna?"
(Discussing hotspots as areas of high variation and endemism is relevant here.)