Biodiversity: Preserving Species

Biodiversity: Preserving Species

Extinction Events

• Mass Extinction Events:

  • Definition: A significant and widespread decrease in the number of species on Earth.

  • Sixth Mass Extinction: Current ongoing extinction event.

  • Historical Context:

  • Holocene Epoch: Began approximately 10,000 years ago.

  • Cenozoic Era: Current geological era which began 66 million years ago.

  • Previously Notable Extinctions:

    • Late Ordovician: 20% of families extinct.

    • Late Devonian: 15% of families extinct.

    • Permian-Triassic: Largest extinction event with significant biodiversity loss.

    • Cretaceous-Tertiary: Notable for the extinction of dinosaurs.

  • Extinction Rates: Rates have varied over millions of years, with major driving forces including climate change and meteorite impacts.

Biodiversity Loss Statistics

• Estimated Number of Species:

  • Mammals: 6,513 (91% evaluated, 22% threatened)

  • Birds: 11,158 (100% evaluated, 13% threatened)

  • Reptiles: 11,341 (75% evaluated, 17% threatened)

  • Amphibians: 8,309 (87% evaluated, 34% threatened)

  • Fishes: 35,797 (61% evaluated, 15% threatened)

  • Insects: 1,053,578 (1% evaluated, 18% threatened)

  • Molluscs: 81,719 (11% evaluated, 26% threatened)

  • Crustaceans: 80,122 (4% evaluated, 23% threatened)

  • Corals: 2,175 (40% evaluated, 27% threatened)

  • Arachnids: 110,615 (0.4% evaluated, 55% threatened)

  • Mosses: 21,925 (1.3% evaluated, 59% threatened)

  • Ferns and Allies: 11,800 (6% evaluated, 39% threatened)

  • Gymnosperms: 1,113 (91% evaluated, 40% threatened)

  • Flowering Plants: 369,000 (14% evaluated, 40% threatened)

  • Fungi, lichens, protists: 141,317 (0.30% evaluated, 57% threatened)

Loss of Biodiversity

• Current Concerns:

  • Endangered Species: 41,415 species listed by the International Union for Conservation of Nature.

  • Most Endangered: Amphibians at 41% threatened.

  • Environmental Factors: Accelerating pollution impacting many species.

Causes of Biodiversity Loss

• Deforestation: 24 million acres lost annually (equivalent to roughly 4/5 of New York).

• Overfishing: Major fishing stocks are collapsing; fish consumption exceeds population growth.

• Wildlife Poaching: Species such as rhinos, elephants, and tigers are particularly affected.

• Invasive Species: Examples include zebra mussels and kudzu vine, which outcompete native species.

• Climate Change: Rising temperatures threaten sensitive ecosystems such as coral reefs.

Invasive Species

• Characteristics:

  • Introduced either intentionally or unintentionally.

  • Lack of natural predators in new environments.

  • Difficult and costly to eradicate.

• Examples:

  • Zebra mussels

  • Kudzu

  • Spotted lanternfly

  • Sea lamprey

Wildlife Poaching

• Cultural and Economic Drivers:

  • Parts of animals (e.g., tiger bones, teeth, skin) used in traditional medicine, jewelry, and status symbols.

  • Demand results in extreme threats to species like tigers.

  • Health vs. Wealth: The insatiable demand for tiger parts fuels poaching more than traditional medicine.

Effects of Loss of Biodiversity

• Ecosystem Degradation:

  • Decrease in essential services such as soil quality, water purification, and carbon storage.

  • Accelerated extinction rates impact food webs.

  • Increased spread of zoonotic diseases (e.g., ebola) due to habitat disruption.

  • Threats to food security as land productivity decreases.

  • Loss of many medicinal plants, highlighted by the example of cinchona trees, which are essential for producing quinine.

Biodiversity Hotspots

• Examples and Their Species Counts:

  • California Floristic Province: 2,125 species

  • Polynesia and Micronesia: 3,334 species

  • Mesoamerican Forest: 5,000 species

  • Tropical Andes: 20,000 species

  • Atlantic Forest: 6,000 species

  • Many hotspots support exceptional biodiversity, highlighting the need for targeted conservation efforts.

Ecosystem Services

• Types of Services:

  • Provisioning Services: Food, fresh water, wood, and genetic resources.

  • Regulating Services: Climate regulation, disease regulation, water purification, and pollination services.

  • Cultural Services: Include spiritual, aesthetic, educational, and recreational benefits.

  • Supporting Services: Nutrient cycling, evolution, soil formation, and ecosystem functions are foundational for other services.

• Valuation: Costanza Paper estimated ecosystem services at $145 trillion/year.

Natural Medicinal Products

• Examples of Medicinal Products:

  • Penicillin: Antibiotic from fungus.

  • Digitalis: Heart stimulant from foxglove.

  • Quinine: Used for malaria treatment from cinchona bark.

  • Corticosteroids: Anti-inflammatory treatments from Mexican yam.

  • Impact of biodiversity on health and medicine emphasizes importance of conservation.

Conservation Efforts

• History: Various treaties, national parks, and organizations have emerged to protect species; examples include:

  • US-Canada Migratory Bird Treaty Act (1918)

  • Yellowstone National Park (1872)

  • Establishment of conservation societies such as Audubon in early 1900s.

CITES (Convention on International Trade in Endangered Species)

• Overview:

  • Formed in 1975, countries voluntarily join.

  • Goal is to establish laws to ensure that trade does not threaten wild populations.

  • Inspectors are given powers to check permits; can ban some species trades.

  • Limitations: Does not address habitat loss, and proposals can be rejected.

UN Convention on Biological Diversity (CBD)

• Established in 1993 with goals:

  • Conservation of biodiversity

  • Sustainable use of its components

  • Fair sharing of benefits from genetic resources.

  • Goals are unmet, with a current target set for 30% of Earth's land to be protected by 2030.

Challenges of Biodiversity Treaties

• Key Issues:

  • Lack of enforcement mechanisms.

  • Need for international cooperation amidst illegal wildlife trade.

US-Specific Laws: Endangered Species Act (ESA)

• Enacted in 1973:

  • Regulates hunting, trapping, and harassing of endangered or threatened species.

  • Protects critical habitats, including on private lands.

  • Recovery plans developed post-listing; potential costs of $5 billion per species.

  • Average U.S. allocation approximately $150 million/year for protection and recovery.

• Categories of Species:

  • Endangered: Immediate danger of extinction.

  • Threatened: Likely to become endangered.

  • Vulnerable: Naturally rare or decreased in population.

ESA Case Studies and Controversies

• Columbia River Salmon impacted by dams; cost-benefit analyses arise on whether species preservation is worth economic costs.

• Gray Wolves: History of population recovery leading to de-listing and re-listing highlights complexities in conservation and human-wildlife conflict.

Charismatic Species Preservation

• Protection Trends: Focus often shifts to species perceived as noble, such as dolphins or grizzly bears, neglecting broader ecosystem health considerations.

Alternative Conservation Methods

• Seed Banks: Used for preserving genetic information and resources.

• Zoos & Aquariums: Aim for educational outreach and preservation of genetic material; face challenges in successful captive breeding and reintroduction.

• The urgency of biodiversity preservation through informed policy and conservation efforts is emphasized.