Transcript CH 17 Preserving Biodiversity

Chapter 17
Preserving Earth’s Biological Diversity
Overview of Chapter 17
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Biological Diversity
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Endangered and Extinct Species
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Where is Declining Diversity the Greatest
Problem
Human Causes of Species Endangerment
Conservation Biology
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Why we need organisms
Protecting and Restoring Habitats
Conservation Policies and Laws
Wildlife Management
Biological Diversity
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Biological Diversity
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Number, variety and variability of Earth’s
organisms
Consists of three components:
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Genetic diversity (right)
Species richness
Ecosystem diversity
Why We Need Organisms
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Example contributions to human life:
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Food
Clothing
Shelter
Pollination of crops
Antibiotics and medicines
Biological processes (nitrogen fixation)
Biological Diversity represents an untapped
resource for future uses
Ecosystem Services and Species
Richness
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All organisms are interrelated
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Linked to each other and the physical
environment
Ecosystem services
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Important environmental benefits that
ecosystems provide to people
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Clean air
Clean water
Fertile soil
Removal of a species from a community can
decrease ecosystem services
Scientific Importance of Genetic
Diversity
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Genetic Engineering
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Incorporation of genes from one organism into
a different species
Provided:
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new vaccines
More productive farm animals
Agricultural plants with desirable characteristics
Depends on genetic diversity from which it
obtains genes (cannot create genes)
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Important to protect this diversity
Medical Importance of Organisms
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Genetic Resources are important to
pharmaceutical industry
Ex: Rosy Periwinkle (right)
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Produces chemicals
effective against
certain types of
cancer
Ex: aquatic sponge
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Produces derivative
for the drug AZT
used to treat
AIDS
Agricultural and Industrial Importance
of Organisms
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Agricultural Importance
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Numerous species that are nutritionally
superior to the food we eat
Industrial Importance
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Depends on products from organisms
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Oils and lubricants
Perfumes and fragrances
Dyes
Paper and lumber
poisons
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Extinction
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Extinct Species
Elimination of a species from Earth
Extinct Species
Endangered and Threatened Species
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Earth’s biological diversity is disappearing
at an unprecedented rate
Endangered Species
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Species that faces threats that may cause it
to become extinct within a short period
Threatened Species
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Species whose population has declined to the
point that it may be at risk of extinction
Characteristic of Endangered Species
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Extremely small (localized) range
Requiring a large territory
Living on an island
Having a low reproductive success
Small population size
Low reproductive rates
Requiring specialized breeding areas
Having specialized feeding habitats
California Condor
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Scavenger bird
Requires large,
undisturbed territory
1983- only 22 birds
1987-1992- no longer
found in nature
1992- reintroduced to
nature from zoos
Currently- 200 condors
in nature
Where is Declining Biological Diversity
the Greatest Problem?
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Concern throughout the US
US- Most serious in:
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Hawaii (63% of species at risk)
California (29% of species at risk)
Globally- Most serious in tropical rain
forests
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South and Central America
Central Africa
SE Asia
Earth’s Biodiversity Hotspots
Human Causes of Species Endangerment
Human Cause- Land Use Change
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Destruction, fragmentation or degradation
of habitats
Little habitat remains for many endangered
species
Human Cause- Invasive Species
Human Cause- Overexploitation
Human Cause- Pollution
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Examples: Acid rain, ozone depletion,
climate warming, excessive fertilizer,
industrial wastes
Case-In-Point Disappearing Frogs
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Amphibians are indicator
species
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In US 38% of amphibian
species are declining
No single cause has been
identified
Deformities have also
been identified (right)
Conservation Biology
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Scientific study of how humans impact
organisms and the development of ways to
protect biodiversity
Involves:
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Protecting habitats
Restoring damaged or destroyed habitats
Zoos, aquaria, botanical gardens
Seed banks
Protecting Habitats
Restoring Damaged Habitats
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Restoration ecology
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Benefits
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Study of the historical condition of a humandamaged ecosystem
Goal is to return it to its former state
Creates biological habitats
Regeneration of soil damaged by agriculture or
mining
Disadvantages
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Expensive
Take a long time to restore an area
Restoring Damaged Habitats
Left: (1935) Early
stages of prairie
restoration
Right: (current
day) restored
prairie
Zoos, Aquaria and Botanical Garden
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Save organisms from
extinction
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Artificial
insemination
Embryo transfer
Surrogate mothers
(right)
Goal is to
reintroduce
organisms back to
their natural habitat
Seed Banks
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Stored seeds are
safe from habitat
destruction, climate
warming, etc.
Can use seed banks
to reintroduce
extinct plant species
Some seeds cannot
be stored
Conservation Policies and Laws
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Endangered
Species Act
(ESA)
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1973
Authorized
protection of
endangered
and
threatened
species
Conservation Policies and Laws
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Endangered Species Act
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Species are designated as endangered or
threatened based on biological grounds
Controversial Legislation
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Does not provide compensation for private property
owners who suffer financial loss
Was not reauthorized in 1992 as scheduled
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Private property rights vs. conservation
Financial cost of law
Conservation Policies and Laws
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Habitat Conservation Plans
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1982 Amendment to ESA
Way to resolve conflicts between development
interests and protection of endangered species
Landowner may take a rare species
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IF taking does not threatened the survival of
recovery of the species on that property
Landowner must set aside land for species
Conservation Policies and Laws
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International Conservation:
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World Conservation Strategy (1980)
Convention on Biological Diversity
Convention on International Trade and
Endangered Species of Wild Flora and Fauna
(CITES) (1975)
Wildlife Management
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Application of conservation principles to
manage wild species and their habitats for
human benefit or for the welfare of other
species
Different priorities than conservation
biology
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Wildlife managers concerned with common
species
Conservation biologist concerned with
threatened or endangered species
Wildlife Management
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Migratory Animals
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Ex: Artic Snow Geese- increase in population
has damaged much of Arctic fragile coastal
ecosystem (below)
Wildlife Management
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Aquatic Organisms
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Freshwater fishes
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Must be managed to ensure they are not
overexploited to the point of extinction
Laws regulate time of year, size of fish and
maximum allowable catch
Ocean fishes
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Ocean fisheries often viewed as common
property
Many whale species have been harvested to
point of commercial extinction
You Can Make A Difference
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Increase public awareness of the
importance of biological diversity
Join and actively support conservation
organization
Inform state and national politicians of
desire to have conservation research
funded with tax dollars
Establish parks by writing to national
lawmakers
Control pollution