Introduction to Biodiversity

• Definition: Biodiversity is the variety and variability among living organisms and the ecological complexes in which they occur.

• Importance: Critical for food, ecosystem health, and human survival; biodiversity loss is a significant global issue.

Extinction of Species

• Current Crisis: Biodiversity loss leads to decreased evolutionary capabilities for survival in changing environments.

• Estimates of Species: Between 1.7 and 1.8 million known species, but actual numbers may range from 5 to 50 million.

• Major Taxonomic Groups:

  • Insects: 1,025,000

  • Plants: 270,000

  • Mammals: 4,650

Levels of Biodiversity

1. Genetic Diversity: Variation within species; enables adaptation and resilience.

2. Species Diversity: Variety of species in a region, measured by species richness and evenness.

3. Community and Ecosystem Diversity: Varies among ecosystems; higher diversity leads to greater stability and productivity.

Conservation Strategies

• In Situ Conservation: Protects biodiversity in natural habitats (National Parks, Wildlife Sanctuaries).

• Ex Situ Conservation: Conservation outside natural habitats (Botanical Gardens, Seed Banks).

• Biosphere Reserves: Areas promoting sustainable economic development, conservation, and research.

Biodiversity Hot Spots

• Criteria for Hot Spots: Areas with high endemism and significant habitat loss.

• India's Hot Spots: Western Ghats and Eastern Himalaya, rich in endemic species.

Benefits of Biodiversity

• Ecosystem Services: Essential for nutrient cycling, climate regulation, pollination, etc.

• Uses of Biodiversity: Provides food, pharmaceuticals, and raw materials; aesthetic and cultural values.

Threats to Biodiversity

1. Habitat Destruction and Fragmentation: Primary causes of biodiversity loss.

2. Pollution: Degrades habitats and influences species survival.

3. Invasive Species: Exotic species can threaten native populations.

4. Overexploitation: Hunting and poaching lead to species extinction.

5. Climate Change: Alters habitats and affects species populations.

Man-Wildlife Conflicts

• Causes: Habitat destruction leads to wildlife intrusions; retaliation by locals can endanger species.

• Examples of Conflict: Man-elephant conflicts causing casualties and harm to both parties.

International Efforts and India

• Global Initiatives: Earth Summit in 1992 initiated international biodiversity conservation efforts.

• India's Contributions: Efforts to conserve native species through various governmental and community programs.

Important Terminology

• Biodiversity: Totality of genes, species, and ecosystems.

• Endemic Species: Species found only in a specific geographic area.

• Hot Spots: Regions with significant levels of biodiversity under threat.