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					Biodiversity
   Mr. Kling
• “The worst thing that can happen during the
  1980s is not energy depletion, economic
  collapse, limited nuclear war, or conquest by
  totalitarian government. As terrible as these
  catastrophes would be for us, they can be
  repaired within a few generations. The one
  process ongoing in the 1980s that will take
  millions of years to correct is the loss of
  genetic and species diversity by the destruction
  of natural habitats. This is the folly our
  descendants are least likely to forgive us.”
  - E. O. Wilson, testifying before Congress in
  support of the Endangered Species Act, 1982
       What is Biodiversity?
• 1. Species Diversity - The number of
  different species within a given area or
  habitat.
• 2. Habitat Diversity – The number of
  different habitats per unit area that a
  particular ecosystem or biome contains.
• 3. Genetic Diversity – The range of genetic
  material present in a species or population.
How did we get our Biodiversity?
• Speciation
  – Process by which genetic traits in the
    population occur in response to environmental
    pressure.
• Caused by natural selection
  – Often the result of isolation of populations
  – Sometimes the result of behavioral differences
  – Can take VERY long periods of time
            What is at stake?
• 1/4 of bird species are extinct.
• The following are threatened:
  –   24% of mammal species
  –   12% of bird species
  –   25% of reptile species
  –   30% of fish species
• The rate of species extinction today is
  estimated at 100 to 1000 times the normal
  rate at which species disappear.
               Definitions
• Extinct Species: No longer exists.
• Endangered Species: Has so few
  individual survivors that the species could
  soon become extinct.
• Threatened Species: Still abundant, but
  because of declining numbers is likely to
  become endangered in the near future.
• Extirpated: Locally extinct.
• Endemic species: Those only found in one
  place.
• Hotspot: Region with a high abundance of
  biodiversity.
• Keystone Species: Have a large effect on
  their environment.
   International Union for the
  Conservation of Nature (IUCN)
• Publishes the annual Red List, the world
  standard for listing the world’s threatened
  species.
• www.iucnredlist.org
Quantitative Measure of Biodiversity
• Simpson’s reciprocal
  index
• Measures both number of
  species present (species
                                    N ( N  1)
  richness) and the
                                 D
                                     n(n  1)
  abundance of each
  (species evenness)
• 1 is the lowest biodiversity
  and a higher value means
  greater biodiversity
     Threats to Biodiversity - IB
• Habitat degradation, fragmentation and loss
   – It is estimated 80% of species loss is due to habitat
      destruction.
• Natural hazard events (ie: volcanoes, drought)
• Global catastrophic events (ie: ice age, meteor impact)
• Pollution
• Overexploitation
   – poaching
   – overharvesting
   – collecting
• Introduction/escape of non-native (exotic) and genetically
  modified species
• Modern agriculture (tends toward monoculture)
• Spread of disease
                         HIPPO
    (5 major causes of species decline - AP)
•   Habitat Destruction, Degradation, and Fragmentation
•   Invasive Species
•   Pollution
•   Population Growth (Human)
•   Overexploitation
    Risk Factors for becoming an
     Endangered Species (AP):
• K-strategist – low reproductive potential
• Specialized niche
• Have a small range – Example: live on an island
• Require a large territory – Ex: Grizzly Bears
• Feed at high trophic levels – Ex: Bald Eagle
• Unique behaviors
• Valuable Parts – Snow leopard, rhinoceros, bengal
  tiger
• “The first species to go are the big, the slow, the
  tasty, and those with valuable parts such as tusks
  or skins.” –E.O. Wilson
         Risk Factors for becoming an
           Endangered Species (IB):
•   Narrow geographical range
•   Small population size or declining numbers
•   Low population densities and large territories
•   Few populations of the species
•   A large body
•   Low reproductive potential
•   Seasonal migrants
•   Poor dispersers
•   Specialized feeders or niche requirements
•   Hunted for food or sport
  Causes of Premature Extinction

         Habitat                                          Pollution
          loss                 Overfishing

   Habitat degradation       Climate change              Commercial
    and fragmentation                                hunting and poaching
  Introducing                                             Sale of exotic pets
                         Predator and pest control
nonnative species                                        and decorative plants

                         Secondary Causes



                            •Population growth
                            •Rising resource use
                            •No environmental
                             accounting
                            •Poverty
                            Basic Causes



                                                                      Fig. 9-7, p. 190
Reasons to Preserve Biodiversity
• Direct Values
   – Food Sources
   – Natural products
• Indirect Values
   –   Ecosystem productivity
   –   Scientific and educational value
   –   Biological control agents
   –   Genes
   –   Environmental monitors
   –   Recreation
   –   Human health
   –   Human rights (indigenous people)
   –   Ethical/intrinsic value
           Nature’s Economy
• Biodiversity provides direct economic
  benefits.
  –   Agriculture
  –   Fishing
  –   Forestry
  –   Nature-based tourism
  –   Recreation
           Pharmaceuticals
• 1/3 of all prescription drugs are derived
  from chemical compounds originally found
  in nature.
• 10 of the 25 best-selling drugs are nature’s
  invention.
Nature’s Pharmacy




                    Fig. 9-6, p. 189
    Pharmaceutical Potential
• The saliva of the vampire bat is used to
  unclog arteries.
• There are MANY other possibilities to
  explore!
• Most plant and coral species have yet to be
  tested for their medicinal properties.
             Aldo Leopold
• “A thing is right when it tends to preserve
  the integrity, beauty and stability of the
  biotic community.” -A Sand County Almanac
• One of the most remarkable ideas of our
  time: that the role of humans is not to
  conquer the land, but to be a citizen of it.
• This is known as the “Land Ethic”
     Approaches to Protecting
          Biodiversity
• Conservation Biology: The sustainable use
  and management of natural resources.
  Sustainable harvesting and hunting are
  permitted.
• Preservation Biology: Attempts to exclude
  human activity in areas where humans have
  not yet encroached. Non-anthropocentric
  viewpoint.
       Sustaining Biodiversity:
        The Species Approach
• Identify endangered and threatened species.
• Create a plan to restore their populations to
  historical levels, or some other goal based
  upon current realities.
• Protect one species at a time.
       Sustaining Biodiversity:
      The Ecosystem Approach
• A strategy for the integrated management of
  land, water and living resources that
  promotes conservation and sustainable use
  in an equitable way.
• If you protect the habitat, they will come.
       Island Biogeography
• Protected areas may become “islands”
  within a country and will normally lose
  some of their biodiversity.
• Typically, we observe that a 90% loss of
  habitat causes a 50% loss of the species
  living in the habitat.
• We need to create wildlife corridors to
  prevent this form happening.
   Designing Protected Areas
• SLOSS Debate: Single Large Or Several
  Small
• See page 129 Fig. 6.6
         In-situ Conservation
         (on-site conservation)
• Protecting endangered species in their
  natural habitat.
  – Ex: wildlife refuges and other protected areas
• Maintains populations in the surrounding
  where they developed their unique
  properties.
• Helps ensure the ongoing processes of
  evolution and adaptation.
         Ex-situ Conservation
         (off-site conservation)
• Removing an endangered species and
  protecting in a new location under the care
  of humans. Often used as a last resort.
  – Ex: zoos, aquariums, botanical gardens,
    arboreta, wildlife farms, seed banks.
• Used as a last resort.
• Serve to educate the public and gain support
  for wildlife conservation.
“We need a million Noah’s with a
million arks.” –Thomas Friedman
         Biodiversity Laws
• Endangered Species Act (1973)
• Convention on International Trade in
  Endangered Species (CITES Treaty) –
  ratified by over 150 nations.
• Marine Mammal Protection Act (1972)
    Organizations Dedicated to
     Preserving Biodiversity
• World Wildlife Fund (WWF) – non-
  governmental organization
• United Nations Environment Programme
  (UNEP) – governmental organization
 World Conservation Strategy
• The World Conservation Strategy was published
  in 1980. It emphasized that humanity, which exists
  as a part of nature, has no future unless nature and
  natural resources are conserved. It asserted that
  conservation cannot be achieved without
  development to alleviate the poverty and misery of
  hundreds of millions of people. Stressing the
  interdependence of conservation and development,
  the WCS first gave currency to the term
  "sustainable development".
• "An apt analogy for this problem is a
  man prying rivets out of the wing of an
  airplane so that he can sell the rivets--he
  sees no reason to worry about the
  consequences of his action since he has
  already removed numerous rivets from
  the wing with no ill effect."
  - Walter Reid, Keeping Options Alive: the
  scientific basis for conserving biodiversity,
  (World Resources Institute), 1989 p.55

				
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