Biodiversity Hotspots: Protecting the Most Critical Regions on Earth

Roughly 60% of the world’s plant, bird, mammal, reptile, and amphibian species are packed into areas that cover just 2.5% of Earth’s land surface. These are not random patches of wilderness – they are biodiversity hotspots, the most biologically rich and simultaneously most threatened regions on the planet. Understanding what makes these areas so critical, where they are, and why protecting them is so difficult is central to any serious discussion of global conservation strategy.

Defining biodiversity hotspots 🔗

The concept was introduced by British ecologist Norman Myers in 1988, when he published a landmark paper identifying ten tropical forests characterized by both exceptional plant endemism and alarming rates of habitat loss. Conservation International adopted Myers’ framework as its institutional blueprint in 1989, and by 1999, a rigorous global assessment had established the two precise criteria still used today.

To qualify as a biodiversity hotspot, a region must satisfy both conditions simultaneously. First, it must harbor at least 1,500 species of vascular plants as endemics – species found nowhere else on Earth. Second, it must have already lost 70% or more of its original natural vegetation, leaving no more than 30% of its primary habitat intact. This dual threshold is intentional: high endemism alone is not enough. The region must also be under severe, documented threat. A hotspot, in other words, is both irreplaceable and imperiled.

As confirmed by a foundational study published in Nature, as many as 44% of all vascular plant species and 35% of species across four vertebrate groups are concentrated in these hotspots, which together occupy only a tiny fraction of Earth’s land surface. The forests and remnant ecosystems within hotspots also account for approximately 35% of all ecosystem services on which vulnerable human populations directly depend – from clean water and food to climate regulation and flood control.

Major biodiversity hotspots worldwide 🔗

There are currently 36 recognized biodiversity hotspots globally. The list has evolved over time: 10 were originally identified by Myers in 1988, and the most recently added is the North American Coastal Plain, recognized in 2016. Together, these regions were once far more extensive but have collectively lost around 85% of their original habitat area due to human activity.

The Tropical Andes 🔗

No hotspot on Earth surpasses the Tropical Andes in sheer biological richness. Stretching along the western spine of South America through Venezuela, Colombia, Ecuador, Peru, and Bolivia, this region is referred to by the Critical Ecosystem Partnership Fund as the global epicentre of biodiversity. It is home to roughly one-sixth of all plant species on Earth, with approximately 15,000 endemic plant species alone. Among birds, the hotspot supports over 1,700 species, a third of them found nowhere else – a record for avian diversity across all global hotspots. The extreme variation in elevation, from Amazonian lowlands to glaciated peaks above 6,000 metres, produces a mosaic of distinct ecosystems including tropical rainforests, cloud forests, high-altitude páramos, and dry woodlands, each with its own community of specialized species.

The Western Ghats and Sri Lanka 🔗

Running approximately 1,600 kilometres along the western edge of peninsular India and continuing into Sri Lanka’s central highlands, the Western Ghats hotspot is one of the world’s eight “hottest hotspots.” Despite covering a relatively small geographic area, it contains over 7,400 species of flowering plants, 508 bird species, and 131 amphibian species – the majority of which are found nowhere else. The region is also a UNESCO World Heritage Site and hosts a significant share of India’s tiger and Asian elephant populations.

Madagascar and the Indian Ocean Islands 🔗

Madagascar is frequently cited as one of the most extraordinary examples of evolutionary isolation. Over 80% of the plant and animal species on the island are found nowhere else on the planet. This extraordinary endemism is the result of Madagascar’s geological separation from the African mainland roughly 88 million years ago, allowing its flora and fauna to evolve along entirely independent paths.

Sundaland 🔗

Sundaland encompasses the Malay Peninsula, Borneo, Sumatra, Java, and surrounding islands in Southeast Asia. It is among the most species-rich hotspots on Earth, harboring around 25,000 vascular plants with about 60% endemism. Critically endangered species including the orangutan, Sumatran tiger, and Bornean pygmy elephant call this region home. The hotspot faces mounting pressure from oil palm and pulp wood production, which continue to drive the destruction of its ancient lowland rainforests.

Conservation challenges and opportunities in hotspots 🔗

Protecting hotspots is not simply a matter of drawing boundaries around wild land. These regions sit at the intersection of extreme biological value and intense human pressure. The challenges are structural, ecological, and economic – and they require equally multidimensional responses.

Habitat fragmentation 🔗

One of the most serious and pervasive threats to hotspot biodiversity is habitat fragmentation – the process by which continuous forests and ecosystems are broken into smaller, isolated patches by roads, agriculture, settlements, and infrastructure. Fragmentation does not simply reduce habitat area; it reshapes ecological dynamics entirely. Isolated fragments are exposed to edge effects, where the microclimate and species composition at the boundary of a forest patch differs sharply from its interior. Species adapted to deep forest interiors – many of which are endemic – are disproportionately harmed. Studies on bird species within fragmented Andean forests found measurable physical asymmetry linked to the stress of living in broken habitats. Small fragments also cannot sustain viable populations of wide-ranging mammals, increasing inbreeding risk and reducing genetic diversity over time.

Invasive species 🔗

Invasive species pose a particularly severe threat in hotspots with high endemism, especially island systems. Endemic species that evolved in isolation often lack the defenses needed to survive competition from or predation by introduced organisms. Introduced cats and rats have driven numerous island bird species to extinction. In the Tropical Andes, climate change is projected to expand the range of invasive plant species into high-altitude páramo ecosystems, compounding pressure on endemic vegetation already stressed by warming temperatures. Managing invasive species requires sustained, coordinated effort – there is rarely a permanent or low-cost solution.

The case for targeted investment 🔗

Conservation resources are finite. The hotspot framework exists precisely because it provides a rational basis for prioritizing where limited funds can have the greatest impact. The Critical Ecosystem Partnership Fund (CEPF), a coalition of major conservation donors, directs grants specifically to civil society organizations working within hotspots on the logic that even relatively modest investments in these regions can produce disproportionately large conservation outcomes. The approach is also justified by human welfare: the 36 hotspots are home to approximately 2 billion people, many of them among the world’s poorest, who depend directly on healthy ecosystems for food, water, and income. Conservation that fails to account for these communities is unlikely to succeed in the long run.

Hotspots in India: a case study 🔗

India’s ecological significance is difficult to overstate. The country covers just 2.4% of Earth’s land surface but supports nearly 8% of global biodiversity, including more than 18,000 species of flowering plants and thousands of animal species. This richness is reflected in the fact that four of the world’s 36 biodiversity hotspots fall within or extend into India’s boundaries: the Himalayas, the Indo-Burma region, the Western Ghats, and Sundaland (represented in India by the Nicobar Islands). India is also ranked among the world’s 17 megadiverse nations – a separate but related designation for countries that together account for the vast majority of Earth’s species.

The Himalayas 🔗

The Himalayan hotspot spans the entire arc of the mountain range, covering approximately 750,000 square kilometres across India, Nepal, Bhutan, and adjacent areas. The dramatic vertical rise from below 500 metres at the foothills to over 8,000 metres at the highest peaks creates a stacked series of ecosystems: alluvial grasslands and subtropical broadleaf forests at lower elevations, temperate and conifer forests at mid-altitudes, and alpine meadows and glaciers above the tree line. The hotspot is home to around 300 mammal species, 980 bird species, and over 10,000 plant species, with approximately 3,160 of those plants being endemic. Iconic animals including the snow leopard, red panda, Bengal tiger, and Indian rhinoceros are found within the hotspot’s range. Threats include deforestation for agriculture, rapid infrastructure development including roads and dams, glacial retreat driven by climate change, and in some areas, political instability that complicates protected area management.

The Indo-Burma region 🔗

The Indo-Burma hotspot is one of the largest, covering parts of northeastern India – including Assam, Arunachal Pradesh, Manipur, Mizoram, Meghalaya, Nagaland, and Tripura – along with Myanmar, Thailand, Laos, Cambodia, Vietnam, and portions of China and Malaysia. The Indian section of this hotspot is characterized by lush tropical evergreen, semi-evergreen, and moist deciduous forests, as well as wetlands and river floodplains. Six large mammal species new to science were discovered within the Indo-Burma hotspot over the past two decades, illustrating how much of its biodiversity remains incompletely documented. The region faces severe pressure from commercial logging, illegal wildlife trade, wetland conversion for aquaculture, and dam construction that alters river systems. Conservation efforts include the protection offered by Kaziranga and Manas National Parks, both UNESCO World Heritage Sites.

The Western Ghats 🔗

The Western Ghats stretch roughly 1,600 kilometres along India’s western coast from Gujarat in the north to the southern tip of Kerala, covering over 160,000 square kilometres. Designated a UNESCO World Heritage Site, the region contains 39 protected areas and accounts for approximately 27% of India’s total flora. Its amphibian diversity is particularly remarkable – 131 species have been recorded, with over 114 confined exclusively to the Ghats. The Western Ghats also support roughly 30% of Asia’s elephant population and a significant proportion of the world’s wild tigers. Key conservation threats include encroachment for agriculture (particularly tea, coffee, and rubber plantations), hydroelectric projects that fragment river ecosystems, mining, and road expansion that breaks wildlife corridors.

Sundaland (Nicobar Islands) 🔗

India’s contribution to the Sundaland hotspot comes through the Nicobar Islands, the southernmost part of the Andaman and Nicobar archipelago in the Bay of Bengal. Though they represent just 0.25% of India’s geographical area, the islands are home to more than 10% of the country’s known fauna species. Dominated by tropical evergreen forests and mangroves, the Nicobars host a range of endemic terrestrial species as well as rich marine ecosystems including coral reefs. The region’s geographical isolation has been both a driver of endemism and a partial protection against large-scale human disturbance, though the 2004 Indian Ocean tsunami caused significant damage, and increasing infrastructure development and tourism pressure remain ongoing concerns.

Why hotspots matter beyond conservation 🔗

Biodiversity hotspots are not simply repositories of rare species – they are functioning ecosystems that deliver essential services to human populations. Watershed protection, carbon sequestration, agricultural pollination, climate buffering, and the provision of medicinal compounds are all ecosystem services concentrated within hotspot regions. The overlap between hotspot geography and maps of human dependency on nature is not coincidental: these places evolved under conditions that made them extraordinarily productive, and the people living within them have depended on that productivity for generations. Effective conservation of hotspots therefore serves both ecological and human welfare goals simultaneously – making the case for investment not only on ethical grounds, but on practical ones as well.

What do you think? Given that biodiversity hotspots are home to billions of people who depend on these ecosystems for their livelihoods, how should conservation strategies balance ecological protection with the economic needs of local communities? And with only 36 globally recognized hotspots, does concentrating conservation resources in these areas risk neglecting biodiversity that exists outside them?

References

1. https://www.cepf.net/our-work/biodiversity-hotspots/hotspots-defined
2. https://www.nature.com/articles/35002501
3. https://www.conservation.org/priorities/biodiversity-hotspots
4. https://lacgeo.com/tropical-andes-biodiversity-hotspot
5. https://www.wwfindia.org/about_wwf/priority_species/
6. https://fiveable.me/conservation-biology/unit-1/global-biodiversity-hotspots-conservation-priorities/study-guide/PCWIX2iH8ABsWyNA
7. https://en.wikipedia.org/wiki/Tropical_Andes
8. https://www.perspectecolconserv.com/en-mapping-threat-projecting-invasive-plant-articulo-S253006442400052X
9. https://www.clearias.com/biodiversity-hotspots-in-india/
10. https://www.naturesafariindia.com/biodiversity-hot-spots-in-india-and-around-the-world/
11. https://pwonlyias.com/biodiversity-hotspots-india/
12. https://www.nextias.com/blog/biodiversity-hotspots/
13. https://inclusiveias.com/biodiversity-hotspots-upsc/