Chapter 17 Preserving Earth

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Chapter 17Preserving Earths Biological Diversity
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Overview of Chapter 17

• Biological Diversity
• Why we need organisms
• Endangered and Extinct Species
• Where is Declining Diversity the Greatest Problem
• Human Causes of Species Endangerment
• Conservation Biology
• Protecting and Restoring Habitats
• Conservation Policies and Laws
• Wildlife Management

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Biological Diversity

• Biological Diversity
• Number, variety and variability of Earths
  organisms
• Consists of three components
• Genetic diversity (right)
• Species richness
• Ecosystem diversity

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Why We Need Organisms

• Example contributions to human life
• Food
• Clothing
• Shelter
• Pollination of crops
• Antibiotics and medicines
• Biological processes (nitrogen fixation)
• Biological Diversity represents an untapped
  resource for future uses

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Ecosystem Services and Species Richness

• All organisms are interrelated
• Linked to each other and the physical environment
• Ecosystem services
• Important environmental benefits that ecosystems
  provide to people
• Clean air
• Clean water
• Fertile soil
• Removal of a species from a community can
  decrease ecosystem services

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Scientific Importance of Genetic Diversity

• Genetic Engineering (around since mid-1970s)
• Incorporation of genes from one organism into a
  different species
• Provided
• new vaccines
• More productive farm animals
• Agricultural plants with desirable
  characteristics
• Depends on genetic diversity from which it
  obtains genes (cannot create genes)
• Important to protect this diversity

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Medical Importance of Organisms

• Genetic Resources are important to pharmaceutical
  industry
• Ex Rosy Periwinkle (right)

• Produces chemicals effective against certain
  types of cancer
• Ex aquatic sponge
• Produces derivative for the drug AZT used to
  treat AIDS

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Why are snakes important?

• drugs based on snake venom proteins and are used
  to prevent heart attacks.
• eptifibatide, is a modified rattlesnake venom
  protein.
• tirofiban and is based on a venom protein from
  the African saw-scaled viper.

• Brazilian pit viper venom
• protein in the venom that blocked the action of a
  compound called angiotensin-converting enzyme
  (ACE), which the body uses to keep blood pressure
  at the right level.

Experimental Drug Derived From Snake Venom Shows
Promise In Reversing Effects Of Stroke
(ScienceDaily 1999)
Snake Venom May Slow Cancer Growth, Studies Hint
(National Geographic 2004)
http//www.fasebj.org/cgi/reprint/18/3/421e
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Agricultural and Industrial Importance of
Organisms

• Agricultural Importance
• Numerous species that are nutritionally superior
  to the food we eat
• Industrial Importance
• Depends on products from organisms
• Oils and lubricants
• Perfumes and fragrances
• Dyes
• Paper and lumber
• poisons

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Extinction

• Background extinction (low level)
• has occurred continuously during the time in
  which organisms have occupied the Earth
• Mass extinctions (numerous species disappear over
  short period)
• have only occurred maybe five or six times
• Causes not well understood
• It is greatly accelerated by human activities
  Earths biological diversity is disappearing at
  an unprecedented rate (100X to 1000X)

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Extinct Species

• Extinction
• Elimination of a species from Earth

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Extinct Species
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Endangered and Threatened Species

• Earths biological diversity is disappearing at
  an unprecedented rate
• Endangered Species
• Species that faces threats that may cause it to
  become extinct within a short period
• Threatened Species
• Species whose population has declined to the
  point that it may be at risk of extinction
  (likely to become endangered).

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Characteristic of Endangered Species

• 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

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Characteristic of Endangered Species

• Endemic species are at great risk
• 155/171 bird species that have become extinct
  were endemics (island populations)
• How is habitat fragmentation like an island?
• How can wildlife corridors help?

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California Condor

• 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

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Eastern Diamondback Rattlesnake
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Where is Declining Biological Diversity the
Greatest Problem?

• Concern throughout the US
• US- Most serious in
• Hawaii (63 of species at risk)
• California (29 of species at risk)
• Globally- Most serious in tropical rain forests
• South and Central America
• Central Africa
• SE Asia

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Earths Biodiversity Hotspots (Norman Myers)
As many as 44 of all species of vascular plants,
29 of bird species, 27 of endemic mammal
species, 38 of endemic reptile species, and 53
of endemic amphibian species live within
biodiversity hotspots
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Human Causes of Species EndangermentMillennium
Ecosystem Assessment
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Human Cause- Land Use Change

• Destruction, fragmentation or degradation of
  habitats
• Little habitat remains for many endangered species

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Human Cause- Invasive SpeciesForeign species
whose introduction causes economic or
environmental harm
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Human Cause- Overexploitation

• Species can become endangered or extinct as a
  result of deliberate efforts to eradicate or
  control their numbers
• Illegal commercial hunting, or poaching,
  endangers many larger animals
• Many unique animals and plants are threatened by
  commercial harvesting

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Human Cause- Pollution

• Examples Acid rain, ozone depletion, climate
  warming, excessive fertilizer, industrial wastes

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Case-In-Point Disappearing Frogs

• Amphibians are indicator species- provide an
  early warning of environmental damage with the
  potential to affect other species
• In US 38 of amphibian species are declining
• No single cause has been identified
• Deformities have also been identified (right)

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Conservation Biology

• Scientific study of how humans impact organisms
  and the development of ways to protect
  biodiversity
• Involves
• Protecting habitats (In situ)
• Restoring damaged or destroyed habitats (In situ)
• Zoos, aquaria, botanical gardens (Ex situ)
• Seed banks (Ex situ)

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Protecting Habitats
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Restoring Damaged Habitats

• Restoration ecology
• Study of the historical condition of a
  human-damaged ecosystem
• Goal is to return it to its former state
• Benefits
• Creates biological habitats
• Regeneration of soil damaged by agriculture or
  mining
• Disadvantages
• Expensive
• Take a long time to restore an area

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Restoring Damaged Habitats
Left (1935) Early stages of prairie restoration
Right (current day) restored prairie
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Zoos, Aquaria and Botanical Garden

• Save organisms from extinction
• Artificial insemination
• Embryo transfer
• Surrogate mothers (right)
• Goal is to reintroduce organisms back to their
  natural habitat
• Success varies

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Seed Banks

• Stored seeds are safe from habitat destruction,
  climate warming, etc.
• Can use seed banks to reintroduce extinct plant
  species
• Some seeds cannot be stored

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Conservation Organizations

• World Conservation Union, World Wildlife
  Foundation, and The Nature Conservancy
• Essential in the effort to maintain biological
  diversity
• These groups help educate policymakers and the
  public

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Conservation Policies and Laws

• Endangered Species Act (ESA)
• 1973
• Authorized protection of endangered and
  threatened species
• Over 1300 species protected

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Conservation Policies and Laws

• Endangered Species Act
• Species are designated as endangered or
  threatened based on biological grounds
• Controversial Legislation
• Does not provide compensation for private
  property owners who suffer financial loss
• Was not reauthorized in 1992 as scheduled
• Private property rights vs. conservation
• Financial cost of law
• Costs too much for benefit supplied to species

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Conservation Policies and Laws

• Habitat Conservation Plans (HCP)
• 1982 Amendment to ESA
• Way to resolve conflicts between development
  interests and protection of endangered species
• Landowner may take a rare species
• IF taking does not threatened the survival of
  recovery of the species on that property
• Landowner must set aside land for species
• Do not assure recovery
• May actually contribute to extinction

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International Conservation Policies and Laws

• International Conservation
• World Conservation Strategy (1980)
• designed to conserve biological diversity
  worldwide
• Convention on Biological Diversity
• decrease the rate of extinction of the worlds
  endangered species signatory nation to inventory
  its own biodiversity and develop a national
  conservation strategy
• Convention on International Trade and Endangered
  Species of Wild Flora and Fauna (CITES) (1975)
• bans hunting, capturing, and selling of
  endangered or threatened species and regulates
  the trade of organisms listed as potentially
  threatened

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Wildlife Management

• 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
• Wildlife managers concerned with common species
• Conservation biologist concerned with threatened
  or endangered species

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Wildlife Management

• It includes the regulation of hunting and fishing
  and the management of food, water, and habitat
• Wildlife managers manipulate the plant cover,
  food, and water supplies of a specific animals
  habitat

http//www.wilddog.com.au/content/files/images/pho
tos/PEOPLE/Wild-Dog-deer-hunter.jpg
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Wildlife Management

• Migratory Animals
• established by international agreements
• Ex Artic Snow Geese- increase in population has
  damaged much of Arctic fragile coastal ecosystem
  (below)

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Wildlife Management

• Aquatic Organisms
• Must be managed to ensure they are not
  overexploited to the point of extinction
• Freshwater fishes
• Laws regulate time of year, size of fish and
  maximum allowable catch
• Ocean fishes
• Ocean fisheries often viewed as common property
• Many whale species have been harvested to point
  of commercial extinction

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You Can Make A Difference

• 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