Biodiversity: Hotspots | Zoology Optional Notes for UPSC PDF Download

Biodiversity Hotspots: A Vital Conservation Concept

• A biodiversity hotspot refers to a biogeographic region that serves as a critical reservoir of biodiversity while facing imminent threats of destruction.
• Coined by British biologist Norman Myers in 1988, these hotspots encompass 36 biologically rich areas worldwide, each of which has lost a minimum of 70% of its original habitat.

Conservation International's Role

• Conservation International (CI), a U.S. non-profit environmental organization headquartered in Arlington, Virginia, adopted Myers' hotspots concept in 1989.
• In 1996, CI initiated a comprehensive review, introducing quantitative criteria for hotspot designation.
• CI's primary goal is to safeguard nature, recognizing its significance as a source of food, clean water, livelihoods, and a stable climate.

• A region must meet two strict criteria to be considered a hotspot:
  1. It must contain at least 1,500 species of vascular plants, amounting to over 0.5% of the world's total species, as endemics.
  2. It must have suffered a minimum loss of 70% of its original habitat.

• In 1999, CI identified 25 biodiversity hotspots in their book "Hotspots: Earth's Biologically Richest and Most Endangered Terrestrial Eco-regions."
• Surprisingly, these hotspots constitute merely 1.4% of the world's land surface but support nearly 60% of the planet's plant and animal species.
• Approximately 44% of the world's plants and 35% of terrestrial vertebrates found in these areas are endemics.
• In 2005, CI published an updated version titled "Hotspots Revisited: Earth's Biologically Richest and Most Endangered Terrestrial Eco-regions."

Twenty five biodiversity hotspots of the world

Evolution of the Hotspot Concept

• Biodiversity hotspots serve as a critical method for identifying regions requiring immediate attention to combat biodiversity loss and guide conservation investments.
• CI's 2004 revision solidified the current hotspot system.
• Over time, new hotspots have been periodically added based on scientific assessments and evolving circumstances. For instance, the Forests of East Australia were added as a hotspot when research validated their qualification.
• Continuous habitat loss or the discovery of new species may lead to future re-assessments, potentially expanding the list of hotspots.

Hotspot Criteria: Qualifying for Biodiversity Hotspots

1. Endemic Plant Species Requirement: It should house a minimum of 1,500 species of vascular plants, accounting for more than 0.5% of the world's total plant species, as endemics.
2. Habitat Loss Threshold: The hotspot must have experienced a substantial loss of its original native habitat, equal to or exceeding 70%.

1. Global Significance: Biodiversity hotspots are of paramount global importance, serving as repositories of invaluable natural treasures.
2. Extraordinary Biodiversity: These regions are exceptionally rich in genetic diversity, species diversity, or a combination of both.
3. Endemic and Endangered Species: They are habitats for endemic and endangered species, exhibiting high levels of endemism while being under significant threat due to habitat destruction, which may lead to species extinctions.

Out of the 36 global biodiversity hotspots, two are located in India: the Eastern Himalayas and Western Ghats.

Salient Features of Indian Biodiversity Hotspots

1. Eastern Himalayas: This region boasts an incredibly diverse topography, resulting in a high level of forest species diversity and endemism.

   • Numerous deep and semi-isolated valleys in Sikkim are particularly rich in endemic plant species.
   • The forest cover in the Eastern Himalayas has declined to approximately one-third of its original extent.
   • Some species, such as Sepia himalayas, a parasitic organism, have been sighted only twice in this region over the past 70 years.

2. Western Ghats: Extending along a 17,000 km strip across Maharashtra, Karnataka, Tamil Nadu, and Kerala, the Western Ghats is characterized by remarkable endemism.

   • It is home to 40% of India's total endemic plant species, with 62% of amphibians and 50% of lizards found in this region being endemic.
   • Notably, several species are common to both Indian hotspots.

• Shared plant species include Lernstroemia japonica, Rhode drum, and hyponym, emphasizing the unique flora present in these regions.