Chapter 31: Conserving Earth's Biodiversity

Introduction

• Definition of conservation biology: Scientific discipline focused on preserving Earth's biodiversity.
• Importance of biodiversity: Genetic, species, and ecosystem diversity.

Why is Biodiversity Important?

• Economic Reasons

  • Ecosystem services: Benefits from ecosystems include provisioning (raw materials, food, energy), regulating (water purification, climate regulation), cultural (recreation, tourism), and supporting services (photosynthesis, soil formation).
  • Economic value: Estimated at $125 trillion per year.

• Keystone Species

  • Importance in ecosystem functioning.

Major Threats to Biodiversity

• Extinction

  • Historical context: 99.9% of all species extinct; five mass extinction events.
  • Current situation: Potential sixth mass extinction, driven by environmental change (habitat destruction, increased competition).

• Threatened Species Classification

  • Endangered versus threatened versus local and global extinction.

• Habitat Loss & Fragmentation

  • Human activities: Agriculture, urban development, mining.
  • Importance of continuous habitats.
  • Minimum viable population concept.

• Overexploitation

  • Unsustainable harvesting practices (e.g., cod in New England).
  • Impact on species with restricted habitats and low growth rates.

• Invasive Species

  • Examples: Japanese knotweed, multifloral rose.
  • Impact of non-native species on local ecosystems.

• Pollution

  • Synthetic chemicals: Pesticides, flame retardants, BPA.
  • Toxic metals: Mercury, lead.
  • Historical example: DDT and biomagnification in birds.
  • Nutrient runoff: Phosphorus and nitrogen causing algal blooms.

• Climate Change

  • Amplifying effects of habitat loss and overexploitation.

Mitigation Strategies

• Wildlife Corridors
  • Example: Overpass connecting fragmented habitats.

Sustainability

• Moral and practical reasons to protect biodiversity.
• Sustainable Development
  • Definition: Meeting present needs without compromising the future.
  • Practices in sustainable agriculture: Soil erosion control, pest management, crop diversity.

Sustainable Practices for Individuals

• Energy conservation: Heating, cooling, lighting.
• Material conservation: Recycling, reusing.
• Water conservation.
• Minimization of chemical use.
• Informed choices: Food, clothing.
• Community engagement: Volunteering, education, voting, and supporting conservation efforts.

These notes cover the major topics and points discussed in the preview video for Chapter 31 on conserving Earth's biodiversity, focusing on the importance, threats, and sustainable practices related to biodiversity conservation.