Important Biodiversity Hotspots and Ecoregions in India

Biodiversity hotspots are biogeographic regions that possess exceptionally high levels of species richness and endemism, while facing severe habitat loss and environmental degradation. To qualify as a biodiversity hotspot under the criteria established by Conservation International, a region must contain at least 1,500 species of vascular plants as endemics and must have lost at least 70% of its primary native vegetation. Out of the 36 globally recognized biodiversity hotspots, four cover parts of India: the Himalayas, the Indo-Burma region, the Western Ghats, and Sundaland. These ecological zones host distinct ecoregions ranging from alpine meadows and tropical rainforests to estuarine mangroves and arid scrublands.

Global Criteria and Indian Distribution

The hotspot concept, introduced by British ecologist Norman Myers in 1988 and refined in 2000, identifies areas where exceptional biodiversity overlaps with high human impact. India covers approximately 2.4% of the world’s land area while accounting for nearly 8% of global recorded species.

Qualifying Thresholds for Hotspots

• Endemism Target: The territory must harbor a minimum of 1,500 species of endemic vascular plants, representing more than 0.5% of the world’s total plant species.
• Habitat Threat Target: The geographic zone must have lost 70% or more of its original primary habitat, leaving 30% or less of its original natural cover intact.

Overview of India’s Four Biodiversity Hotspots

• The Himalayas: Spans the entire Indian Himalayan region across Jammu and Kashmir, Ladakh, Himachal Pradesh, Uttarakhand, Sikkim, West Bengal, and Arunachal Pradesh.
• Western Ghats: Extends along the western coast through Gujarat, Maharashtra, Goa, Karnataka, Tamil Nadu, and Kerala.
• Indo-Burma Region: Encompasses all northeastern states east of the Brahmaputra River (excluding parts of Assam), including Manipur, Mizoram, Nagaland, Tripura, Meghalaya, and the Andaman Islands.
• Sundaland: Includes the Nicobar Group of Islands, extending southward into South-East Asian archipelagos.

The Four Major Biodiversity Hotspots in India

Each hotspot houses distinct topographical features, endemic flora, threatened fauna, and protected area networks.

1. The Himalayas

• Geographic Extent: Covers the northern boundary of India, dividing into the Western and Eastern Himalayas. It rises from the Indo-Gangetic plains to high alpine peaks.
• Ecological Features: Transitions from subtropical pine forests at lower altitudes to temperate broadleaf forests, subalpine conifer forests, and high-altitude alpine meadows.
• Endemic Flora and Fauna: Key species include the Snow Leopard, Red Panda, Himalayan Tahr, Musk Deer, Kashmir Stag (Hangul), and Himalayan Monal.
• Key Protected Areas: Great Himalayan National Park (Himachal Pradesh), Valley of Flowers National Park (Uttarakhand), Hemis National Park (Ladakh), and Khangchendzonga National Park (Sikkim).

2. Western Ghats (Sahyadri Mountains)

• Geographic Extent: A continuous mountain chain running parallel to the western coast of India over a length of approximately 1,600 km.
• Ecological Features: Blocks southwest monsoon winds, generating high rainfall that supports tropical wet evergreen, semi-evergreen, and moist deciduous forests. The higher elevations feature unique montane grasslands known as Shola ecosystems.
• Endemic Flora and Fauna: Home to the Lion-tailed Macaque, Nilgiri Tahr, Malabar Giant Squirrel, Nilgiri Langur, Lion-tailed Macaque, and Purple Frog (Nasikabatrachus sahyadrensis). It holds over 5,000 species of flowering plants, with nearly 30% endemic to the region.
• Key Protected Areas: Silent Valley National Park (Kerala), Mudumalai National Park (Tamil Nadu), Bandipur National Park (Karnataka), and Periyar Tiger Reserve (Kerala).

3. Indo-Burma Region

• Geographic Extent: Covers North-East India (south of the Brahmaputra River), including the Patkai, Naga, Lushai, and Khasi-Jaintia hills, alongside the Andaman Islands.
• Ecological Features: Characterized by tropical evergreen, semi-evergreen, and bamboo forests, with high freshwater biodiversity.
• Endemic Flora and Fauna: Hosts the Hoolock Gibbon (India’s only ape), Sangai Deer (Brows-antlered deer), Golden Langur, Pygmy Hog, Hispid Hare, and White-winged Wood Duck.
• Key Protected Areas: Keibul Lamjao National Park (Manipur), Kaziranga National Park (Assam), Namdapha National Park (Arunachal Pradesh), and Nokrek National Park (Meghalaya).

4. Sundaland

• Geographic Extent: Extends into India via the Nicobar Islands in the Bay of Bengal, lying close to the Sumatra archipelago.
• Ecological Features: Dominated by tropical coastal rainforests, littoral vegetation, and pristine coral reef systems.
• Endemic Flora and Fauna: Species include the Nicobar Megapode, Nicobar Tree Shrew, Great Nicobar Serpent Eagle, and Saltwater Crocodile. It serves as a critical nesting site for Leatherback Sea Turtles.
• Key Protected Areas: Campbell Bay National Park and Galathea National Park on Great Nicobar Island.

Major Ecoregions in India

An ecoregion represents a large unit of land or water containing a geographically distinct assemblage of natural communities and species. The World Wide Fund for Nature (WWF) identifies several distinct terrestrial, freshwater, and marine ecoregions within India.

Key Terrestrial Ecoregions

• Terai-Duar Savanna and Grasslands: Located along the southern foothills of the Himalayas across Uttarakhand, Uttar Pradesh, Bihar, West Bengal, and Assam. Features tall elephant grass (Saccharum ravennae) and sal forests. Key species: Indian Rhinoceros, Bengal Tiger, and Swamp Deer (Barasingha).
• Sundarbans Mangroves: Located in the Ganges-Brahmaputra Delta in West Bengal. It represents the largest contiguous mangrove forest block in the world. Key species: Royal Bengal Tiger, Estuarine Crocodile, and Gangetic Dolphin.
• Rann of Kutch Seasonal Salt Marsh: Located in Gujarat. Divided into the Great Rann and Little Rann, forming an arid salt flat environment during dry months and a shallow wetland during monsoons. Key species: Indian Wild Ass (Khur) and Greater Flamingo.
• Deccan Thorn Scrub Forests: Spans the rain-shadow region of the Deccan Plateau across Andhra Pradesh, Telangana, Karnataka, and Maharashtra. Key species: Great Indian Bustard, Blackbuck, and Sloth Bear.
• Eastern Highlands Moist Deciduous Forests: Extends across Odisha, Chhattisgarh, Andhra Pradesh, and Jharkhand. Dominated by Sal (Shorea robusta) and Teak (Tectona grandis). Key species: Wild Water Buffalo and Gaur.

Comparative Profile of Indian Hotspots

Core Facts on Indian Biodiversity

• Global Hotspots Count: There are 36 designated biodiversity hotspots worldwide, with 4 overlapping Indian territory.
• First Hotspot Concept: Proposed by Norman Myers in 1988 to prioritize conservation actions in areas with high endemic plant species loss.
• Only Indian Ape: The Hoolock Gibbon is found in the Indo-Burma hotspot region of Northeast India.
• Floating National Park: Keibul Lamjao National Park on Loktak Lake in Manipur is the world’s only floating national park, home to the endangered Sangai deer.
• Unique Grassland-Forest Complex: Shola forests are tropical montane stunted forests found in high-altitude valleys separated by rolling grasslands in the Western Ghats.
• Megadiverse Country Status: India is recognized as one of the 17 megadiverse countries in the world due to its high concentration of global biodiversity.
• Western Ghats UNESCO Status: The Western Ghats was inscribed as a UNESCO World Heritage Site in 2012 as a collection of 39 individual protected sites.
• Largest Mangrove Forest: The Sundarbans holds the title of the world’s largest deltaic mangrove ecosystem, split between India and Bangladesh.
• Wild Ass Habitat: The Little Rann of Kutch serves as the sole remaining natural habitat for the Indian Wild Ass (Equus hemionus khur).
• Great Nicobar Biosphere Reserve: Forms the northernmost limit of the Sundaland hotspot, protecting the Galathea and Campbell Bay national parks.