Conservation Biology Notes

Biodiversity Crisis

  • Humans have significantly altered the Earth, leading to a potential sixth mass extinction, termed the "Anthropocene," and a "biodiversity crisis."

Conservation Biology

  • Conservation biology is an applied science focused on preserving species, habitats, and ecosystem services.
  • It integrates ecology, physiology, molecular biology, genetics, economics, and evolutionary biology.
  • Conservation biology is distinct from environmentalism, though it can inform related policies.

Four Levels of Biodiversity

  • Genetic diversity: Variation within and between populations.
  • Species diversity: Variety of species in an ecosystem or the biosphere.
  • Ecosystem diversity: Variety of ecosystems in the biosphere.
  • Taxonomic Diversity: loss of unique families, orders, or classes of organisms.

Genetic Diversity

  • Genetic diversity is declining in natural and cultivated species.
  • Low genetic diversity in crops can threaten food security.

Species Diversity

  • Endangered species are at risk of extinction throughout their range.
  • Threatened species are likely to become endangered.

Ecosystem Diversity

  • Human activities are decreasing ecosystem diversity.

Justifications for Biodiversity Conservation

  • Self-interest: Includes food, recreation, materials, scientific value, water supply, and climate regulation.
  • Ethical, aesthetic, and spiritual motivations.

Self-Interest

  • Wild species can improve agricultural crops genetically.
  • Many pharmaceuticals are derived from plants.
  • Ecosystem services include air and water purification, waste detoxification, nutrient cycling, and climate moderation.

Threats to Biodiversity

  • Habitat destruction and fragmentation
  • Changes in ecosystem processes
  • Introduced species
  • Overharvesting
  • Global change

Habitat Destruction and Fragmentation

  • Habitats are being destroyed; remaining habitats are often fragmented.
  • Fragmented habitats support smaller, more vulnerable populations with less genetic variation.

Habitat Change and Disruption of Ecosystem Processes

  • Altered ecosystem processes negatively impact natural habitats.

Introduction of Exotics

  • Exotic species can cause native species extinctions.

Overexploitation

  • Overexploitation can lead to extinction.

Species Vulnerability to Extinction

  • Endemism
  • Rarity
  • Small population size
  • Ecological specialization
  • Usefulness to humans or competition with humans

Weighing Conflicting Demands

  • Conservation often involves balancing the needs of endangered species with human economic demands.

Commercial Whaling

  • The International Whaling Commission (IWC) aims to conserve whale stocks.
  • Moratoriums on whaling face resistance due to economic and cultural factors.

Establishing Protected Areas

  • Protected areas are crucial for slowing biodiversity loss.
  • Large reserves vs. numerous small reserves is a key consideration.

Conflicting Demands

  • Managing land use and introduction of species.

Monarch Butterfly Biosphere Reserve

  • Preserves overwintering sites and restricts land use to sustain the site.