Lecture Notes: Biodiversity and Conservation

Key Topics

• Definition of biodiversity
• Origins of biodiversity
• Threats to biodiversity
• Conservation efforts
• Connection to environmental value systems

Biodiversity

• Definition
  • Broad umbrella concept includes:
    • Habitat diversity
    • Species diversity
    • Genetic diversity
• Components
  • Habitat Diversity: Range of different habitats available in an ecosystem.
  • Species Diversity: Includes species richness (number of species) and evenness (abundance of species).
  • Genetic Diversity: Range of genetic material in a gene pool.

Species Diversity

• Stability in ecosystems often linked to even species distribution.
• Example: Community with even species distribution is more stable than one dominated by a single species.

Biodiversity Hotspots

• Areas with high biodiversity and species endemism.
• Example: Tropical rainforests.
• Threats include rapid loss (e.g., deforestation).

Threats to Biodiversity

• Human Impact
  • Deforestation and habitat destruction.
  • Overhunting.
  • Introduction of exotic species.
• Biodiversity Loss
  • Human activity causing first biotic mass extinction.
• Factors Making Species Prone to Extinction
  • Small populations.
  • Specialists with specific dietary needs.
  • Large mammals targeted for poaching.
  • Poor competitors, charismatic vs. non-charismatic species.

Evolution and Speciation

• Evolution
  • Gradual genetic changes over generations.
  • Driven by natural selection.
• Speciation
  • Formation of new species through isolation (geographical, mechanical, behavioral, genetic).

Mass Extinctions

• Five past mass extinctions due to abiotic factors (e.g., climatic changes).
• Current extinction driven by humans (biotic factors).

Conservation

• Conservation Efforts
  • Importance of valuing resources (direct use, existence, bequest values).
  • Justifications include aesthetic, ecological, economic, ethical, and social.

Connection to Environmental Value Systems

• Conservation linked to how resources are valued and prioritized.
• Importance of environmental education and different value systems in conservation strategies.