Biodiversity Hotspots in India

Biodiversity includes the diversity of plant and animal species within a specific habitat. It consists of two important components: species evenness and species richness. India is well-known for its diverse ecosystem, with around twenty-three point thirty-nine percent of its land covered by trees and forests. The nation is home to nearly ninety-one thousand identified animal species and forty-five thousand five hundred documented plant species.

What is Biodiversity?

Biodiversity or biological diversity includes the variety of living species on Earth, including plants, animals, bacteria, and fungi. The term biological diversity was used first by an American botanist, Arthur Harris in 1916. The term, “biodiversity” was coined by Walter G. Rosen in 1985. Generally, biodiversity is divided into three fundamental categories: genetic diversity, species diversity, and ecosystem diversity.

What are Biodiversity Hotspots?

The term ‘biodiversity hotspot’ was coined by Norman Myers (1988) who recognized 10 tropical forests as “hotspots” according to the level of plant endemism and high level of habitat loss. It, however, did not have any quantitative criteria for designating a region’s ecological hotspot.

• Two years later, he added eight more hotspots, which increased the number of hotspots in the world increased to 18.
• The Conservation International (CI) associated with Myers made the first systematic update of the hotspots.
• CI then introduced the following two strict quantitative criteria, for a region to qualify as a hotspot:
  • It should contain at least 1,500 species of vascular plants (> 0.5% of the world’s total) as endemics.
  • It must have lost ≥ 70% of its original native habitat.

Biodiversity Hotspots in India

India’s rich biodiversity, covering approximately 24.46% of its geographical area with forests and trees, includes “Biodiversity hotspots” as coined by Norman Myers. These hotspots are regions known for high species richness and endemism, making them crucial topics for the IAS Exam under the UPSC Mains GS-III syllabus. This article explores India’s major biodiversity hotspots and provides a list of IUCN endangered species, essential for aspirants preparing for the exam. A downloadable PDF of notes is also available at the end of the article.

Out of the 36 biodiversity hotspots in the world, 4 are in India which includes the Himalayas, the Western Ghats, the Indo-Burma region, and the Sundaland.

The Himalayas

• Overall, the Himalayas comprise North-East India, Bhutan, and Central and Eastern parts of Nepal.
• These Himalayan Mountains are the highest in the world and host some of the highest peaks in the world including Mount Everest and K2.
• It also includes some of the major rivers of the world like Indus and Ganga.
• Himalayas hosts almost 163 endangered species including one-horned rhinoceros, wild Asian water buffalo, and as many as 45 mammals, 50 birds, 12 amphibians, 17 reptiles, 3 invertebrates, and 36 plant species.

The Western Ghats

• These hills are found along the western edge of peninsular India.
• As the region is mountainous and oceanic, it receives a good amount of rainfall.
• Around 77% of the amphibians and 62% of the reptiles are endemic.
• Moreover, the region is also home to around 450 species of birds, 140 mammals, 260 reptiles, and 175 amphibians.

Indo-Burma region

• This region consists of various countries including North-Eastern India (to the south of the Brahmaputra River), Myanmar, China’s Yunnan provinces, Lao People’s Democratic Republic, Vietnam, Cambodia, and Thailand.
• Almost 13,500 plant species can be spotted in the region, half of which are endemic and cannot be found in any other place in the world.
• Although this region is quite rich in biodiversity, the situation has been worsening over the past few decades.

Sundaland

• This region lies in Southeast Asia and includes Thailand, Singapore, Indonesia, Brunei, and Malaysia.
• Nicobar region represents India in this hotspot.
• UNESCO declared this region as the World Biosphere Reserve in 2013.
• These islands have a rich terrestrial and marine ecosystem including mangroves, seagrass beds, and coral reefs.

High-Biodiversity Wilderness Area (HBWA)

The High Biodiversity Wilderness Areas (HBWA) concept, developed by Conservation International (CI), focuses on five out of the 24 major wilderness areas globally recognized for their significant biodiversity, as outlined by Mittermeier et al (2002). These areas include:

• Amazon Basin, Brazil.
• Congo Basin, The Democratic Republic of Congo.
• New Guinea, Indonesia, and Papua New Guinea.
• North American Deserts, Southwest United States, and Mexico.
• Miombo-Mopane Woodlands and Savannas, Zambia.
• Together, the intact portions of these areas cover 8,981,000 km2, representing 76% of their original extent and accounting for 6.1% of the planet’s land area. The geographic boundaries of the HBWAs align with several amalgamated WWF ecoregions.

Historically, HBWAs were considered to have “low vulnerability” due to minimal past habitat loss. However, recent analyses indicate that the high cultivation potential of many HBWAs makes them susceptible to future agricultural expansion. The expansion of cropland poses a significant threat to biodiversity in tropical countries.