What is a Biodiversity Hotspot?
A biodiversity hotspot is a biogeographic region that is both a significant reservoir of biodiversity and is threatened with destruction. The concept was first introduced by British ecologist Norman Myers in 1988 and later refined by Conservation International.
| Definition (Myers, 1988) A region qualifies as a biodiversity hotspot if it: (1) Contains at least 1,500 species of vascular plants as endemics (≥0.5% of the world’s total), AND (2) Has lost at least 70% of its original natural vegetation. As of 2024, there are 36 biodiversity hotspots worldwide. |
India, with only 2.4% of the world’s land area, accounts for approximately 7-8% of all recorded species. This extraordinary biological richness is reflected in the fact that India hosts 4 of the world’s 36 globally recognised biodiversity hotspots — more than almost any other country.
India’s Four Biodiversity Hotspots
1. Western Ghats
Stretching over 1,600 km along India’s western coast, the Western Ghats (also called the Sahyadri Hills) is one of the world’s 8 ‘hottest hotspots’. This mountain range runs parallel to the Arabian Sea through the states of Gujarat, Maharashtra, Goa, Karnataka, Kerala, and Tamil Nadu.
- Area: ~160,000 sq km (original extent); ~59,000 sq km of natural vegetation remains
- Endemism: Over 5,000 species of flowering plants, 139 mammal species, 508 bird species
- Iconic species: Nilgiri tahr, lion-tailed macaque, Malabar giant squirrel, purple frog
- UNESCO World Heritage Site (2012) — 39 serial properties
- Includes tiger reserves: Anamalai, Kalakad-Mundanthurai, Periyar, BRT
| Key Fact for Exams The Western Ghats is older than the Himalayas and is one of the world’s 10 ‘hottest hotspots’ of biodiversity. The Gadgil Committee (2011) and Kasturirangan Committee (2013) reports are important exam topics related to its conservation. |
2. Eastern Himalayas (Indo-Burma + Himalaya)
The Eastern Himalayas, encompassing the states of Sikkim, Arunachal Pradesh, parts of Assam, Meghalaya, Nagaland, Manipur, Mizoram, and Tripura (the ‘Eight Sister States’), form part of both the Indo-Burma and Himalaya hotspots recognised globally.
- Home to over 10,000 plant species including 900+ orchid species
- Fauna includes snow leopard, red panda, one-horned rhinoceros, clouded leopard
- Highest avian diversity in India — over 500 bird species
- Kaziranga National Park (Assam) — UNESCO World Heritage Site; home to 2/3 of world’s one-horned rhinos
- Manas National Park — UNESCO World Heritage Site; Project Tiger, Project Elephant site
| 🔑 APSC Special Focus For APSC aspirants, Assam falls within the Eastern Himalayan hotspot. Key protected areas include Kaziranga NP, Manas NP, Dibru-Saikhowa NP, and Nameri NP. The Brahmaputra floodplains support unique riverine biodiversity. Questions on the one-horned rhinoceros, river dolphins (Gangetic), and hoolock gibbons are frequently asked. |
3. Indo-Burma Region
The Indo-Burma biodiversity hotspot extends across Myanmar, Thailand, Laos, Cambodia, Vietnam, and the northeastern states of India — particularly Manipur, Mizoram, Nagaland, and Tripura. It is considered one of the most threatened hotspots globally.
- Contains 13,500+ plant species, with 7,000 endemic
- Freshwater biodiversity hotspot — over 1,200 fish species including 553 endemic
- Key Indian species: Sangai deer (brow-antlered deer), Burmese star tortoise, Hoolock gibbon
- The Loktak Lake in Manipur — the only floating national park (Keibul Lamjao NP)
- Threat: One of the fastest rates of deforestation in Asia
4. Sundaland (Andaman & Nicobar Islands)
While the Sundaland hotspot is primarily centred in Southeast Asia (Borneo, Sumatra, Java), India’s Andaman & Nicobar Islands are included within this hotspot. These 572 islands represent India’s most remote and ecologically rich territory.
- Over 2,200 plant species; ~3,000 species of animals
- 322 bird species including endemic Andaman serpent-eagle, Nicobar pigeon
- Dugong (sea cow) — State animal of Andaman & Nicobar Islands
- Coral reefs: Home to 179 coral species; declared biosphere reserve (1989)
- Vulnerable Jarawas, Sentinelese, and other Particularly Vulnerable Tribal Groups (PVTGs)
| 📌 Note The Great Nicobar Island is a UNESCO Biosphere Reserve and an important nesting ground for leatherback sea turtles — the world’s largest turtle. Recent infrastructure development proposals for Great Nicobar have been a matter of significant environmental debate and a potential exam topic. |
Quick Reference: India’s Biodiversity Hotspots at a Glance
| Hotspot | States/Region | Key Species | Threats |
| Western Ghats | Kerala, Tamil Nadu, Karnataka, Goa, Maharashtra | Lion-tailed macaque, Malabar civet, Nilgiri tahr | Agriculture, tourism, hydropower |
| Eastern Himalayas | Sikkim, Arunachal Pradesh, Assam, Meghalaya | Snow leopard, Red panda, one-horned rhino | Deforestation, climate change |
| Indo-Burma Region | NE India (Manipur, Mizoram, Nagaland) | Indochinese tiger, Eld’s deer, Burmese star tortoise | Shifting cultivation, logging |
| Sundaland | Andaman & Nicobar Islands (India portion) | Dugong, Nicobar megapode, saltwater crocodile | Invasive species, overfishing |
Conservation Frameworks and Legal Provisions
International Frameworks
- Convention on Biological Diversity (CBD) — India ratified in 1994
- Nagoya Protocol on Access and Benefit Sharing (ABS) — in force since 2014
- CITES — Convention on International Trade in Endangered Species
- Ramsar Convention — on wetlands of international importance
- UNESCO Man and Biosphere Programme (MAB) — 12 Biosphere Reserves in India under World Network
National Legislation
- Wildlife Protection Act, 1972 (amended 2006, 2022) — provides for protected area network
- Forest Conservation Act, 1980 — regulates diversion of forest land
- Biological Diversity Act, 2002 — implements CBD; establishes National Biodiversity Authority (NBA)
- Environment Protection Act, 1986 — umbrella legislation for environmental protection
- Forest Rights Act, 2006 — recognizes tribal rights in forest areas
Conservation Mechanisms
- Project Tiger (1973) — 54 Tiger Reserves covering ~75,796 sq km
- Project Elephant (1992) — 33 Elephant Reserves
- Project Snow Leopard (2009) — five Himalayan states
- Sea Turtle Project, Crocodile Conservation Project, Vulture Conservation Programme
- National Mission for Green India (NMGI) under NAPCC
UPSC Civil Services Examination: Previous Year Questions
| 🎯 UPSC Exam Insight Biodiversity hotspots appear regularly in both Prelims (GS Paper I) and Mains (GS Paper III – Environment & Ecology). Questions test conceptual clarity, factual knowledge of hotspots, and critical analysis of conservation policies. |
| Year | Question/Topic | Paper |
| 2023 | Discuss the significance of the Western Ghats as a biodiversity hotspot and threats to it. | GS Paper I |
| 2022 | What are biodiversity hotspots? Critically examine India’s role in conservation. | GS Paper III |
| 2021 | Explain the criteria for designation of biodiversity hotspots. Why is NE India significant? | GS Paper I |
| 2019 | Define endemic species. What steps has India taken to protect species in biodiversity hotspots? | GS Paper III |
| 2017 | Sacred groves and their role in in-situ conservation of biodiversity in India. | GS Paper III |
High-Value UPSC Mains Answer Points
- Myers criteria (1,500 endemic plant species + 70% habitat loss) — must-know definition
- Difference between in-situ (national parks, biosphere reserves) and ex-situ conservation (zoos, gene banks)
- Critical link between biodiversity and ecosystem services (provisioning, regulating, cultural, supporting)
- Gadgil-Kasturirangan debate on Western Ghats ESA (Ecologically Sensitive Area) classification
- Role of local communities and PVTGs in conservation — Forest Rights Act linkage
- India’s commitments under CBD COP15: 30×30 target (protect 30% land & sea by 2030)
APSC (Assam Public Service Commission): Special Insights
| APSC Exam Insight For APSC and other Northeastern state PSC exams, detailed knowledge of the Eastern Himalayan hotspot and the biodiversity of Assam and the Northeast is essential. This region features in almost every APSC exam cycle. |
Assam-Specific Biodiversity Facts
- Assam hosts 2 UNESCO World Heritage Sites: Kaziranga NP and Manas NP
- Kaziranga NP: 2,413 sq km; home to ~2,600 one-horned rhinos (as of 2022 census)
- Manas NP: Biosphere Reserve + Tiger Reserve + Elephant Reserve — triply protected
- Dibru-Saikhowa: Only feral horses in the world in their natural habitat
- Assam has the highest density of tigers in India per unit area (Kaziranga)
- Hoolock gibbon — India’s only ape; found in Assam’s forests
- Gangetic river dolphin (Platanista gangetica) — State Aquatic Animal of Assam; National Aquatic Animal of India
- Pobitora Wildlife Sanctuary — Highest density of one-horned rhinos in the world
APSC Previous Year Topics
- Role of wetlands in Assam’s biodiversity — Deepor Beel (Ramsar Site)
- Human-wildlife conflict in Assam: elephant corridors, rhino poaching
- Shifting cultivation (Jhum) and its impact on Northeast biodiversity
- Northeast India as part of both Eastern Himalayan and Indo-Burma hotspots
- Assam’s Biosphere Reserves: Dibru-Saikhowa, Manas, Nokrek (Meghalaya)
- Role of NE India in migratory bird corridors — Central Asian Flyway
Major Threats to India’s Biodiversity Hotspots
Despite robust legal frameworks, India’s biodiversity hotspots face a multitude of anthropogenic and natural pressures:
- Habitat loss and fragmentation: Agricultural expansion, urbanisation, and infrastructure projects (roads, dams, railways)
- Invasive alien species: Lantana camara, Mikania micrantha (‘mile-a-minute weed’), water hyacinth threatening native species
- Climate change: Glacial retreat threatening Himalayan ecosystems; altered monsoon affecting forest composition
- Poaching and wildlife trade: Rhino horn, tiger parts, elephant ivory, medicinal plants
- Human-wildlife conflict: Crop raiding by elephants, predation by big cats along wildlife corridors
- Pollution: Plastic waste in Andaman reefs, pesticide runoff affecting Western Ghats streams
- Shifting cultivation (Jhum): A major factor in Northeast India’s forest degradation
Way Forward: Conservation Strategies
A multi-pronged approach is necessary for effective conservation of India’s biodiversity hotspots:
- Strengthening the protected area network — increasing coverage from current ~5% to the global 30×30 target
- Corridor conservation — creating and protecting wildlife corridors linking fragmented habitats
- Community-based conservation — empowering local communities, recognising rights under FRA 2006
- Technology integration — use of AI, satellite monitoring, camera traps for real-time wildlife tracking
- Restoration ecology — active restoration of degraded ecosystems (wetlands, mangroves, shola forests)
- Climate adaptation — building resilience of hotspot ecosystems against climate change impacts
- International cooperation — strengthening CITES enforcement, ABS implementation under Nagoya Protocol
- Education and ecotourism — sustainable tourism to generate community livelihood and conservation awareness
Conclusion
India’s four biodiversity hotspots — the Western Ghats, Eastern Himalayas, Indo-Burma region, and Sundaland — represent irreplaceable natural heritage. They are not merely ecological zones but repositories of evolutionary history, sources of ecosystem services worth trillions, and cultural landscapes for millions of people.
For UPSC and APSC aspirants, biodiversity hotspots represent a perennially important topic that bridges environment, geography, polity (environmental laws), and international relations (MEAs). A thorough understanding of the biological, geographical, and policy dimensions of these hotspots is essential for scoring well in both Prelims and Mains examinations.
| Exam Strategy For Mains answers on biodiversity, always: (1) Start with a definition/criteria, (2) Provide specific data/statistics, (3) Mention relevant laws or international agreements, (4) Discuss threats with examples, (5) Conclude with way forward. For APSC, always include a Northeast India/Assam-specific dimension wherever possible. |
Quick Revision: Key Facts for Last-Minute Prep
| Fact | Value / Detail |
| Total biodiversity hotspots (global) | 36 (as of 2024) |
| Hotspots in India | 4 |
| Myers’ criteria — endemic plants | ≥ 1,500 vascular plant species |
| Myers’ criteria — habitat loss | ≥ 70% primary vegetation lost |
| India’s land area (% of world) | 2.4% |
| India’s species share (% of world) | ~7-8% |
| Western Ghats UNESCO status | World Heritage Site (2012) |
| Kaziranga — One-horned rhinos | ~2,600 (2022 census) |
| India’s Tiger Reserves | 54 |
| India’s Elephant Reserves | 33 |
| Biosphere Reserves (India) | 18 (12 in UNESCO World Network) |
| National Aquatic Animal of India | Gangetic river dolphin |
| Biodiversity Act year | 2002 |
| CBD ratification by India | 1994 |
| Hottest hotspot (most threatened) | Indo-Burma region |