AP Environmental Science

Biodiversity and the Extinction Crisis

What can you do to preserve biodiversity???

I. What is biodiversity?

A. Definition: number of species on earth or in a particular locality

  • What is biodiversity??
  • The Virtual Zoo -- overview of animal diversity
  • Overview of biodiversity - American Museum of Natural History
  • Wild Finder - explore the world's biodiversity
  • Animal diversity web

    • B. Extent of biodiversity (see also chapter 6-7 notes)

    1. global species composition

    2. 1.4 million known species

    3. estimates range from 10 to 100 million total species.

    4. most “species rich” habitats/biomes are the tropical regions and coral reefs

    5. island biodiversity relates to nearby mainland and the size of the island

    • 90% reduction in area = 50% reduction in species

    II. Threats to biodiversity

    A. history of extinctions

    B. human population growth and resource use are leading to extinctions – in what some have called the “6th major extinction”.

    1. global distribution of extinction threats – fig. 11-4

    2. types of extinctions: local, ecological, biological (text p. 225)

    3. examples of species extinct in recent times – fig. 12-2

    4. examples of species that are currently threatened with extinction – fig. 12-3

    5. characteristics of species that are prone to extinction – fig. 12-4

    6. ecologists debate the actual extinction rate – see discussion p. 228-229

    C. causes of extinctions (fig. 12-6)

  • Overview of threats to biodiversity -- tons of information and data!!
  • check out the endangered species exhibit at the American Museum of Natural History -- without going to New York!
  • hunting may have caused extinctions of several large animal species such as mastodons
  • Check out statistics and maps at Earth Trends

    1. most significant reason is habitat loss: mining, logging, farming, and development (fig. 12-7)

    2. introduction of exotic species – “alien invasions” or “bioinvasions” (fig. 12-9, 12-10, 12-11, 13-5; Kudzu is discussed on p. 234 and termites on 237)

    3. pesticide use and other chemical problems

    4. hunting, poaching, and over-fishing (fig. 12-13)

    • D. Reasons for preservation (p. 229-230)

  • more information

    1. stewardship – Gen. 1:28 and 2:15

    • a group called the Noah Alliance is bringing together people of faith to work on protecting biodiversity

    2. value of species to humans - medicine, food, other products

  • database of medicinal plants
  • some examples
  • drugs from the sea
  • economic - National Wildlife recently reported on economists attempting to calculate the economic value of natural systems
  • economic value of insects
  • more on the economic value of intact ecosystems
  • examples of specific products and processes that have been inspired by living organisms
  • Some sites promoting "urban forestry": Casey Tree Endowment | DC Urban Forestry Administration | Trees Please
  • USDA site on Green Infastructure
  • National Geographic interactive - the value of ecosystems

    • 3. interconnectedness of species (note the quote from A. Leopold).

    4. aesthetic/intrinsic

    5. the Nature Conservancy suggests 10 reasons

    • III. Saving biodiversity

    A. need for large, interconnected habitats

       

    B. zoos, captive breeding programs, botanical gardens, seed banks

    C. legislation/government

    1. biologists, businesspeople, and politicians must work together

    2. Endangered Species Act (see p. 241-244)

    3. CITES - international treaty

    4 The Boreal Forest Framework is a major initiative in Canada aimed at protecting the biodiversity of forests

    D. private conservancy groups

    E. population control and sustainable development (more)

    F. Hybridization causes problems for management of endangered species

    IV. Managing terrestrial biodiversity – chap 11

    A. US Public (federal) land agencies (fig. 11-6)

    1. multiple-use lands permit resource extraction as well as recreation and protecting wildlife

    2. National Wildlife Refuges (Fish and Wildlife Service) are designed to protect wildlife habitat, with recreation and sometimes resource use as secondary goals

    3. National Parks have the most restrictive use policies

    4. Wilderness areas have been designated on all types of federal lands. Humans have no permanent habitation in these areas, and travel is by foot (or paddle) only

                5. marine protected areas have been established in ocean waters and are administered by NOAA

    B. US State lands of often managed with a similar range of goals. Some state lands protect very large areas, such as the Adirondacks in New York (more)

    C. Other countries have designated national parks and forest reserves as well – fig. 11-21

    D. Private organizations have made significant contributions to conserving land and resources – see p. 216 on the Nature Conservancy

    E. Managing public lands often involves controversy

    1. contrasting aims of the two extremes

    2. example – livestock grazing on grasslands | more here

    3. forest management is the most controversial and difficult (see below)

    4. the USGS Biological Resources Division does research to monitor changes in natural habitats

    F. forest management

    1. distribution of forest types – fig. 23-6 and 23-8; also 23-18

    2. ecological and economic services provided by forests – fig. 11-7; also p. 204

    3. tree plantations vs. old-growth forests – p. 199-200

    4. various harvesting methods are used – fig. 11-10 and 11-12

    5. case study in US forest management – p. 209

    6. world-wide harvest trends – p. 203

    7. pathogens are damaging many forests, with both ecological and economic damage (fig. 11-14)

    8. a movement toward sustainable forestry is growing (another link) (see fig. 11-13)

    9. tropical forests face a different set of problems – p. 210-212

    G. Identifying areas most in need of preservation

    1. Gap analysis attempts to identify areas in need of conservation

    2. biodiversity and endangered species hot spots – fig. 11-24 and 12-14

    3. design of core reserves with buffer zones – fig. 11-22

    4. ecological restoration attempts to restore full ecological functions in degraded landscapes. This sometimes involves re-introducing missing native plants and animals, and restoring natural fire patterns – see p. 220-221

    V. Managing aquatic resources and biodiversity – chap 13

    A. Threats to marine biodiversity are similar to those discussed earlier – see p. 255

    B. Many fish species have been severely over-fished - fig. 13-4

    C. other issues

    1. protecting sea turtles - fig. 13-6 and 13-7

    2. whale hunting – p. 259-262

    3. beach erosion

    4. managing fisheries – p. 263-265 (remember the commons idea!!)

    5. protecting and restoring wetlands (more on this later) – p. 265-267

    6. protecting and restoring freshwater lakes and streams (more on this later too) – p. 267-270

    What can you do to preserve biodiversity???