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

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