“Biodiversity” is often defined as the variety of all forms of life, from genes to species, through to the broad scale of ecosystems.
“Biodiversity” was coined as a contraction of “biological diversity” in 1985, but the new term arguably has taken on a meaning and imports all of its own.
A symposium in 1986 and the follow‒up book Biodiversity, edited by biologist E.O. Wilson, heralded the population of this concept.
Ten years later, Takacs described its ascent.
Overall, the major issue for biodiversity is how its conservation may be integrated with other needs of society.
British ecologist Norman Myers defined the biodiversity hotspot concept in 1988 to address the dilemma that conservationists face: what areas are the most immediately important for conserving biodiversity?
The biodiversity hotspots hold especially high numbers of endemic species, yet their combined area of remaining habitat covers only 2.3 per cent of the Earth’s land surface.
Each hotspot faces extreme threats and has already lost at least 70 per cent of its original natural vegetation.
Over 50 per cent of the world’s plant species and 42 per cent of all terrestrial vertebrate species are endemic to the 34 biodiversity hotspots.
A seminal paper by Norman Myers in 1985 first identified ten tropical forest “hotspots” characterized both by exceptional levels of plant endemism and by serious levels of habitat loss.
In 1990, Myers added a further eight hotspots, including four Mediterranean‒type ecosystems.
Conservat‒ ional International adopted Myers’ hotspots as its institutional blueprint in 1989, and in 1996, the organization made the decision to undertake a reassessment of the hotspots concept, including an examination of whether key areas had been overlooked.
Three years later an extensive global review was undertaken, which introduced quantitative thresholds for the designation of biodiversity hotspots: To qualify as a hotspot, a region must meet two strict criteria: it must contain at least 0.5% or 1,500 species of vascular plants as endemics, and it has to have lost at least 70% of its primary vegetation.
Around the world, at least 25 areas qualify under this definition, with nine others possible candidates.
These sites support nearly 60% of the world's plant, bird, mammals, reptile and amphibian species, with a very high share of endemic species.