Biodiversity Hotspots
Hot spots are the richest and most threatened reservoirs of plant and animal life of the earth. They have maximum number of endemic species. They occupy 1.4% of the earth’s surface and 20% of worlds human population lives in these areas. Currently, 35 biodiversity hotspots have been identified, most of which occur in tropical forests.
India hosts 4 biodiversity hotspots: the Western Ghats, the Eastern Himalayas, the Indo-Burma region and the Sundaland.
TO QUALIFY AS A HOT SPOT, A REGION MUST MEET TWO STRICT CRITERIA:
- Species endemism: the region must contain at least 1,500 species of vascular plants (> 0.5% of the world’s total) as endemics, and
- Degree of threat: the region has to have lost at least 70% of its original habitat.
- The biodiversity hotspots are mostly confined to the tropical regions of the world. One idea is that tropical regions harbor greater biodiversity because they are especially fertile grounds for the formation of new species -- i.e., “cradles of diversity.” Another idea is that biodiversity hotspots are less likely to lose the species they already have.
- Biodiversity hotspots do not make allowances for changing land use patterns. Hotspots represent regions that have experienced considerable habitat loss, but this does not mean they are experiencing ongoing habitat loss. On the other hand, regions that are relatively intact (e.g. the Amazon Basin) have experienced relatively little land loss, but are currently losing habitat at tremendous rates.
- Endemic plants,
- Endemic vertebrates,
- Endemic plants/area ratio (species per 100km2),
- Endemic vertebrates/area ratio (species per 100km2) and
- Remaining primary vegetation as % of original extent.
The eight hottest hot spots in terms of the above five factors are:
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Madagascar
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Philippines
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Sundaland [South East Asia]
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Brazil’s Atlantic Forest
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Caribbean
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Indo-Burma
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Western Ghats and Sri Lanka
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Eastern Arc and Coastal Forests of Tanzania/Kenya
These eight ‘hottest hot spots’, appear at least three times in the top ten listings for each factor.