Ecosystems and Biodiversity Notes

The Value of Ecosystems and Biodiversity

  • Ecosystems are vital for food, water, and fiber.

  • Biodiversity is crucial for maintaining planetary processes and human well-being.

  • Ecosystems face threats from natural and human-induced stresses.

  • Protecting ecosystems is essential for the Earth's future.

Core Values of Ecosystems

  • Maintenance of Genetic Diversity

  • Need to Allow Natural Change to Proceed

  • Heritage Values

  • Utility Values

  • Intrinsic Values

  • Remember: HUMIN (Heritage, Utility, Maintenance, Intrinsic, Need)

1. Maintenance of Genetic Diversity

  • Refers to the gene pool, allowing for adaptation and variation within a species.

Natural Selection

  • Darwin's theory: species with best-suited traits are more likely to survive and pass them on.

  • Diversity results from millions of years of evolution.

Loss of Genetic Diversity

  • Loss of a species reduces irreplaceable unique genetic substances.

  • Current extinction rate: one species per day due to human activities.

Increase in Extinctions

  • Rapid rise in extinctions in the last 400 years, with over 700 recorded.

  • Major causes: introducing exotic species, habitat destruction, and predation.

  • Human-induced loss is an opportunity cost of an expanding population.

Opportunity Cost

  • Loss of genetic diversity due to human actions is an opportunity cost.

  • Opportunity cost: sacrifice of genetic diversity to do something else.

Australia's Biodiversity

  • Australia has experienced the largest documented biodiversity decline in the past 200 years.

  • Significant ecosystem loss: rainforests, forests, wetlands, woodlands, and grasslands.

The IUCN Red List Index

  • The IUCN lists over 42,000 species as threatened on its Red List Index (RLI).

  • The RLI categorizes species by extinction threat; lower scores indicate higher risk.

  • RLI is reviewed regularly and can be broken down by various factors.

  • An RLI of 0 indicates extinction.