apes 2/25

Ch. 11 – Biodiversity

Genetic Diversity: variation within a species 

Species Diversity: different organisms within a community

Ecological Diversity: refers to the richness and complexity of a biological community.

• About 1.7 million cataloged species 

• Estimated 3-50 million species in existence 

• About 65% are invertebrate life forms 

• Majority of threatened species are concentrated in the tropics (biodiversity hotspots)

Benefits to Biodiversity

• Food Sources 

• Drugs & Medicines

• Ecological cycles & processes 

• Aesthetic & cultural richness

Biodiversity is constantly changing…

• Extinction: Elimination of a species

  • Naturally occurring process driven by evolution and natural catastrophes (~1 species per decade) 

  • Can be accelerated by human disturbance 

Threats to Biodiversity 

• H.I.P.P.O. (E.O. Wilson)

  • Habitat Destruction 

    • (The single greatest human-caused reduction of biodiversity)

  • Invasive Species

    • Accidentally or intentionally 

  • Pollution

    • Toxic pollutants 

  • Population (of humans)

    • Diseases 

  • Overharvesting

    • Poaching, illegal hunting & fishing, exotic pet trade

Biodiversity Management & Protection 

• Endangered Species Act 

  • Endangered = in imminent danger of extinction

  • Threatened = likely to become endangered 

  • Vulnerable = naturally rare or at risk due to humans 

• Species Recovery Plans 

  • Habitat conservation, protection, and restoration 

• International Wildlife Treaties (C.I.T.E.S.)

Role of Zoos, Preserves, Game Parks, and Botanical Gardens

• Zoologist Geroge Shaller argues for spending money out in the wild instead of on the walls 

02/06 – Ecological Biodiversity: Preserving Landscapes 

Primary Forests (Old Growth Forests)

• Composed primarily of native species in which there is little indication of human activity and ecological processes are not significantly disturbed

• Home to much of the world's biodiversity, ecological services, and indigenous cultures.

• Less than ⅓ of the world’s forest 

• The U.S. has less than 10% remaining

Forest’s many uses (and abuses).

• Construction material

• Paper pulp

• Fuel Wood (~50%)

• Cropland (slash & burn)

• ¼ of the world's forests are managed for wood production, much of it replanted in single-species monoculture forestry. 

• Other threats include climate change, droughts, wildfires, and insect threats

Grasslands 

• Highly desirable for conversion to cropland due to rich soil composition

• Often exploited by livestock overgrazing, which can lead to desertification

Process of Desertification

1. Elimination of most palatable grasses & herbs 

2. Invasion by opportunistic weedy species 

3. Pulverization by hooves, accelerating erosion

Protecting Ecosystem Diversity 

• U.S. National Park Service (1916)

  • Educate the public 

  • Protect the environment 

  • Preserve our natural heritage 

• Threats to our Park System

  • Governmental and business attacks for profit

  • Lack of funding 

  • Overuse (loved to death)

• What is the best Parks Management plan?

  • Core habitat – one of the reasons that large preserves are considered better than small reserves

Landscape Ecology

• Science that examines relationships between spatial patterns and ecological processes such as species movement or survival 

• Variables

  • Habitat size

  • Shape

  • Relative amount of core and edge

  • Surrounding land composition

Specialist species 

• Can only survive in a narrow range of conditions

• Have a limited diet

• Have narrow niches

• Are more prone to extinction

• Examples include pandas and some plants that rely on specific amounts of rainfall

Generalist species 

• plants or animals that can live in many different environments and eat a variety of foods 

• well-adapted to a wide range of conditions, and can be found in many different regions of the world. 

Phylogenetics is the study of how organisms are related to each other through evolution