Biodiversity Hotspots

A biodiversity hotspot is a region with many plant species found nowhere else that has also lost a large share of its natural vegetation. It is a conservation-priority designation based on two requirements: exceptionally high plant endemism and extensive loss of original natural vegetation. A region must satisfy both requirements, not merely have a large number of species.

The two qualifying criteria

A region qualifies only when it meets both of the following quantitative thresholds.

• It must contain at least 1,500 endemic vascular plant species, meaning species naturally restricted to that region and found nowhere else.
• It must have lost at least 70% of its original natural vegetation, meaning that 30% or less of the original vegetation remains.

How to interpret the criteria

The criteria combine irreplaceability with habitat loss: they identify regions whose unique biodiversity could disappear as their natural habitats are destroyed.

• The first criterion measures endemism, not total species richness; a region with many widespread species does not qualify on that basis alone.
• The numerical species threshold concerns vascular plants, not the combined number of plants, mammals, birds and other organisms.
• The vegetation-loss threshold compares remaining natural vegetation with its original extent; it does not mean that 70% of the region's species have become extinct.
• High endemism without the required vegetation loss, or severe vegetation loss without the required endemic plant diversity, is insufficient for qualification.

Why these criteria matter for conservation

Hotspot identification supports conservation prioritisation where resources are limited. Protecting remaining habitats in these regions can help conserve species that cannot be protected elsewhere because their natural ranges are restricted.

• The thresholds identify regional conservation priorities; they are not criteria for determining whether an individual species is endangered.
• A biodiversity hotspot is not itself a legally designated protected area, such as a national park or wildlife sanctuary.
• Regions outside hotspots can still have substantial ecological importance and require conservation; hotspot status is not a complete measure of nature's value.