Norman Myers, a British ecologist, developed the concept of biodiversity hotspots in 1988 to describe a biogeographic region with both exceptional levels of plant endemism and significant levels of habitat loss. The 36 biodiversity hotspots are home to more than half of the world's plant species and 43 percent of all terrestrial vertebrate species. Each biodiversity hotspot represents a remarkable universe of exceptional floral and faunal endemicity struggling to survive in rapidly dwindling ecosystems. In this article, we will discuss the Biodiversity Hot Spots which will be helpful for UPSC exam preparation.

Biodiversity Hot Spots - Background

• Norman Myers, a British ecologist, published a seminal paper identifying 10 tropical forest "hotspots" in 1988. These areas were distinguished by both high levels of plant endemism and severe habitat loss.
• One of CEPF's global donor organizations, Conservation International, adopted Myers' hotspots as its institutional blueprint in 1989.
• In 1996, the organization decided to re-evaluate the hotspots concept, including an examination of whether key areas had been overlooked.
• Three years later, an extensive global review was conducted, which resulted in the designation of 25 biodiversity hotspots based on quantitative thresholds.
• Based on the work of nearly 400 specialists, an additional analysis in 2005 increased the total number of biodiversity hotspots to 34.
• A team of researchers from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) working with Conservation International identified the Forests of East Australia as the 35th hotspot in 2011.
• The North American Coastal Plain was designated as the Earth's 36th hotspot in February 2016 after meeting the criteria.

Criteria to Qualify as Hot Spot

• It must have at least 1,500 endemic vascular plant species (more than 0.5 percent of the world's total) i.e., a high percentage of plant life found nowhere else on the planet. In other words, a hotspot is irreplaceable.
• It must have lost at least 70% of its natural habitat (it must retain 30% or less of its original natural vegetation). To put it another way, it must be threatened.

Distribution of Biodiversity Hot Spots

Hottest Hot Spots

• In terms of endemics, some hot spots are far more abundant than others.
• Five key factors were considered, and the biodiversity hot spots that ranked highest in terms of these five factors were designated as the hottest hot spots.
• The following factors were considered:
  • Endemic plants
  • Endemicvertebrates
  • Ratio of endemic plants/area (species per 100km2)
  • Ratio of endemic vertebrates/area ratio(species per 100km2)
  • Remaining primary vegetation as a percentage of original extent

The top eight hottest hotspots in terms of the above five factors are:

• Madagascar
• Philippines
• Sundaland
• Atlantic Forest of Brazil
• The Caribbean
• Indo-Burma
• Sri Lanka/Western Ghats
• Eastern Arc and Coastal Forests of Tanzania/Kenya

Indian Biodiversity Hot Spots

Following the criteria required for an area to be designated as a Biodiversity Hotspot, India has four major biodiversity hotspots:

• Himalayas
• Indo-Burma Region
• Western Ghats
• Sundaland

Indian Biodiversity Hot Spots

Himalayas

• The Himalayas (overall) comprise North-East India, Bhutan, Central and Eastern Nepal, and are considered the highest in the world.
• This region (NE Himalayas) is home to 163 endangered species, including the Wild Asian Water Buffalo and the One-horned Rhino, as well as 10,000 plant species, 3160 of which are endemic.
• This mountain range encompasses nearly 750,000 square kilometres.

Indo-Burma Region

• The Indo-Burma Region covers a total area of 2,373,000 km2.
• Six large mammal species have been discovered in this region in the last 12 years:
  • Large-antlered Muntjac
  • Annamite Muntjac
  • Grey-shanked Douc
  • Annamite Striped Rabbit
  • Leaf Deer
  • Saola
• This hotspot is also known for its endemic freshwater turtle species, the majority of which are on the verge of extinction due to over-harvesting and habitat loss.
• There are also 1,300 bird species, including the critically endangered White-eared Night-heron, Grey-crowned Crocias, and Orange-necked Partridge.

Western Ghats

• The Western Ghats run along the western edge of peninsular India, encompassing the majority of the deciduous and rain forests.
• According to UNESCO, it is home to at least 325 species of globally threatened flora, fauna, birds, amphibians, reptiles, and fish.
• Originally covering 190,000 km2, the vegetation in this region has been reduced to 43,000 km2.
• The region is also known for its critically endangered flora and fauna, which includes 229 plant species, 31 mammal species, 15 bird species, 43 amphibian species, 5 reptile species, and 1 fish species.
• Of the total 325 globally threatened species in the Western Ghats, 129 are classified as Vulnerable, 145 as Endangered, and 51 as Critically Endangered," according to UNESCO.

Sundaland

• Sundaland is a South-East Asian hotspot that includes Singapore, Thailand, Indonesia, Brunei, and Malaysia.
• The United Nations designated Sundaland as a World Biosphere Reserve in 2013.
• This region is well-known for its diverse terrestrial and marine ecosystems.
• Sundaland is one of the world's biologically richest hotspots, with 25,000 species of vascular plants, 15,000 of which are found only in this region.

*For detailed notes of this topic, check this link Indian Biodiversity Hot Spots

Importance of Biodiversity Hot Spots

• Biodiversity is the foundation of all life on Earth. There would be no air to breathe, no food to eat, and no water to drink if there were no species. There would be no such thing as human society.
• Hotspots are critical to human survival because they are the places on Earth where the most biodiversity is under threat.
• The map of hotspots overlaps extremely well with the map of natural places that benefit people the most.
• Hotspots are home to some of the world's richest and most important ecosystems, as well as many vulnerable populations who rely on nature for survival.
• According to one estimate, despite covering only 2.5 percent of the Earth's land surface, hotspot forests, wetlands, and other ecosystems provide 35 percent of the "ecosystem services" on which vulnerable human populations rely.

List of Biodiversity Hot Spots of World

List of Biodiversity Hot Spots

Conclusion

There are 36 biodiversity hotspots on our planet, and they are stunning, one-of-a-kind, and teeming with life. Plants, animals, and other living organisms that inhabit these areas are rare, and many of them can only be found in these areas. These biodiversity hotspots are currently under threat of destruction. Human-caused habitat destruction, as well as destruction caused by climate change, are the leading causes of the extinction of Earth's species.