Biodiversity hotspot

A biodiversity hotspot is a terrestrial region selected for conservation attention because it combines exceptional plant endemism with extensive loss of natural habitat. The Critical Ecosystem Partnership Fund (CEPF) and Conservation International use two thresholds: a region must contain at least 1,500 endemic species of vascular plants—plants with water- and nutrient-conducting tissues—and must have lost at least 70 percent of its primary native vegetation. In other words, no more than about 30 percent of that original vegetation remains.

The plant threshold supplies a consistent, measurable indicator of irreplaceable biodiversity; it does not imply that animals or other organisms are absent from the assessment. The method focuses on terrestrial regions, and a hotspot is not simply any place with many species: severe habitat loss is part of the definition.

British ecologist Norman Myers introduced the hotspot idea in a 1988 paper that identified ten tropical forest regions where high plant endemism coincided with major habitat loss. Conservation International later adopted the concept and developed quantitative thresholds. A global review in 1999 designated 25 hotspots; subsequent assessments added regions as ecological knowledge and mapping improved. The North American Coastal Plain became the 36th recognized hotspot in 2016.

The currently recognized set comprises 36 regions and covers about 2.5 percent of Earth's land surface, according to Conservation International. The count and boundaries reflect a defined classification and are revised as evidence and assessment methods develop; they are not a claim that only these regions have conservation value.

Hotspot maps are a way to direct limited conservation resources toward places where the loss of habitat threatens species found nowhere else. In their influential 2000 Nature paper, Myers and colleagues used the framework to show how prioritization could focus effort on areas containing many endemic species in a small share of Earth's land. The hotspot label is therefore a planning tool, not a complete measure of biodiversity or a guarantee that funding will protect every species in a region. Other conservation priorities and threatened ecosystems outside designated hotspots remain important.

Hotspots are inhabited landscapes, not empty wilderness. CEPF estimates that around two billion people live in the 36 regions, and many depend directly on healthy ecosystems for livelihoods and well-being. Ecosystems in these areas also provide services such as clean water, pollination and climate regulation. Conservation efforts consequently involve choices about land use, local livelihoods and long-term stewardship as well as protecting species. CEPF works with civil-society groups in hotspot regions, reflecting the importance of local participation in conservation.