Biodiversity hotspot

A biodiversity hotspot must contain at least 1,500 endemic vascular-plant species and retain no more than 30 percent of its original natural vegetation.¹ The criteria, introduced by Norman Myers and colleagues, combine biological irreplaceability with immediate threat rather than ranking regions by species richness alone. Endemism matters because species confined to one region cannot be conserved elsewhere, while habitat loss indicates that the region’s remaining ecosystems face substantial pressure.

The system currently recognizes 36 hotspots across terrestrial regions of the world.² They range from islands and mountain chains to continental ecological mosaics, including the Madagascar and the Indian Ocean Islands, the Cape Floristic Region, the Atlantic Forest, and Indo-Burma. A hotspot is therefore a conservation-priority category, not a formal political boundary or a claim that every part of the region is equally threatened.

Hotspots matter because they concentrate a large share of threatened and geographically restricted life in relatively limited areas. Habitat conversion for agriculture, logging, infrastructure, mining, and urban growth can remove ecosystems faster than species can adapt or relocate. Protecting remaining habitat in a hotspot can consequently prevent multiple extinctions and preserve ecological functions at the same time.

The framework is designed for prioritization, not as a complete measure of global conservation value. Some places with immense biodiversity or major ecosystem services do not meet both hotspot thresholds, while marine environments are not included in the original terrestrial scheme.³ Conservation planning therefore commonly combines hotspot maps with assessments of threatened species, intact ecosystems, freshwater systems, Indigenous territories, and areas important for ecological connectivity.

Hotspot conservation works best when regional protection is paired with local stewardship and durable financing. Protected areas, habitat restoration, wildlife corridors, invasive-species control, sustainable agriculture, and improved enforcement can address different causes of habitat loss. The Critical Ecosystem Partnership Fund supports civil-society groups in biodiversity hotspots, often emphasizing landscape-level planning and community participation.⁴

Designation alone does not create a protected area or guarantee funding. Effective programs must account for land rights, livelihoods, governance, and the distribution of conservation benefits. Indigenous peoples and local communities frequently manage or depend on hotspot landscapes, so conservation that excludes them can produce conflict or fail to protect habitat over the long term. Monitoring of species, forest cover, fires, and land-use change is used to test whether interventions are working.

The hotspot map has changed as better botanical surveys and revised geographic analyses have improved knowledge of endemism and habitat loss.¹ Several hotspots are not continuous blocks of untouched wilderness: they may contain farms, cities, plantations, fragments of forest, and small habitat remnants scattered across a broad biogeographic region. Their designation reflects the region’s historical biological distinctiveness and present level of depletion.

Hotspots also reveal a tension between different conservation priorities. A small island may hold many species found nowhere else, whereas a large tropical forest may support far more total species but fewer narrowly restricted plants per unit area. The framework emphasizes terrestrial plants because they provide a comparatively consistent global indicator, but conservationists also use complementary approaches for animals, fungi, genetic diversity, freshwater biodiversity, and marine environments. These distinctions prevent the label from being mistaken for a universal ranking of nature.

Endemism

The condition in which a species is native to and restricted to a particular geographic area.

Vascular plant

A plant with specialized tissues that transport water and nutrients, including flowering plants, conifers, ferns, and their relatives.

Habitat fragmentation

The division of continuous habitat into smaller, more isolated patches, often through land conversion or infrastructure.

Irreplaceability

The extent to which a site or region contains species or ecological features that cannot be conserved elsewhere.