biodiversity hotspot

The concept of the biodiversity hotspot was introduced by the British ecologist Norman Myers in 1988 in the journal The Environmentalist, and was subsequently refined by Myers and Conservation International (CI) in a landmark 2000 paper in Nature. A region qualifies as a hotspot only if it satisfies two strict criteria simultaneously: it must contain at least 1,500 species of endemic vascular plants (representing more than 0.5% of the world's plant species as endemics), and it must have lost at least 70% of its original primary native vegetation. The dual emphasis on irreplaceability (endemism) and vulnerability (habitat loss) distinguishes hotspots from broader concepts such as biodiversity-rich "megadiverse countries." As of 2026 there are 36 recognised biodiversity hotspots, which together hold the world's remaining habitat of a large share of endemic species while covering only a small fraction of Earth's land surface.

The hotspot framework was designed as a conservation triage tool: because financial and institutional resources are finite, prioritising regions where the greatest endemic diversity faces the greatest threat maximises the biodiversity conserved per unit of investment. Hotspots are concentrated in tropical forests, Mediterranean-type ecosystems, and mountainous regions. Four hotspots have territory in India: the Himalaya, the Indo-Burma region, the Western Ghats–Sri Lanka, and the Sundaland (which includes the Nicobar Islands). The Western Ghats, recognised as a UNESCO World Heritage Site and examined by the Gadgil Committee (2011) and the Kasturirangan Committee (2013), is among the most frequently tested in Indian examinations. Other globally significant hotspots include the Atlantic Forest of Brazil, the Cape Floristic Region of South Africa, Madagascar and the Indian Ocean Islands, and the Tropical Andes—the single richest hotspot in endemic plant terms.

It is important to distinguish the hotspot concept from related designations. Biodiversity hotspots are an NGO-driven prioritisation scheme; they differ from megadiverse countries (a concept promoted by Conservation International and the Like-Minded Megadiverse Countries group formed by the Cancún Declaration, 2002, of which India is a member), and from the IUCN-managed Key Biodiversity Areas and Ramsar wetlands. The framework also complements the Convention on Biological Diversity (1992) and its Kunming-Montreal Global Biodiversity Framework (2022), which set the "30x30" target to protect 30% of land and sea by 2030. Critics note that the hotspot model under-weights non-plant taxa, marine systems, and wilderness areas of low endemism but high ecological intactness.

For the UPSC Civil Services Examination, biodiversity hotspots feature in the General Studies Paper III (environment and ecology) and the Prelims environment segment. Typical question angles include: identifying which Indian regions are hotspots, matching hotspots to their defining criteria (the 1,500-endemic-plant and 70%-loss thresholds), distinguishing hotspots from megadiverse countries, and linking the Western Ghats to the Gadgil and Kasturirangan reports. Candidates should memorise the two quantitative criteria precisely, the number 36, and the four Indian hotspots, as these are the most commonly examined factual hooks.