• Biological hotspots are earth's biologically richest regions that harbour a great diversity of endemic species and have been significantly impacted and altered by human activities.
• Plant diversity is the biological basis for hotspot designation.
• To qualify as a hotspot, a region must meet two strict criteria: it must contain at least 1,500 species of vascular plants (> 0.5 percent of the world‟s total) as endemics, and it has to have lost at least 70 percent of its original habitat.
• Norman Myers in 1988 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.

Hotspots Revisited

• Hotspots: Earth's biologically Richest and Most Endangered Terrestrial Ecoregions (1999), and a year later in the scientific journal Nature (Myers, et al. 2000), 25 biodiversity hotspots were identified.
• The updated analysis (2005) reveals the existence of 34 biodiversity hotspots, each holding at least 1,500 endemic plant species, and having lost at least 70 percent of its original habitat extent.

Coverage

• Overall, the 34 hotspots covered 15.7 percent of the Earth's land surface.
• In all, 86 percent of the hotspots' habitat has already been destroyed, such that the intact remnants of the hotspots now cover only 2.3 percent of the Earth's land surface.
• Examples: 'Western Ghat and Sri Lanka' and 'Eastern Arc Mountain and Coastal Forests' are two examples of biological hotspots.
• Western Ghat and Sri Lanka is the home to 2180 endemic plants and 355 endemic vertebrates whereas Eastern Arc Mountain and Coastal Forests supports 1500 and 121 endemic plants and endemic vertebrates respectively.

Hotspots are not the only system devised for assessing global conservation priorities

• BirdLife International has identified 218 “Endemic Bird Areas” (EBAs) each of which hold two or more bird species found nowhere else.
• The World Wildlife Fund-US has derived a system called the “Global 200 Ecoregions”, the aim of which is to select priority Ecoregions for conservation.
• All hotspots contain at least one Global 200 Ecoregion and at least one EBA;
• 60 percent of Global 200 terrestrial Ecoregions and 78 percent of EBAs overlap with hotspots.