Biodiversity

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Biodiversity
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Outline

• Biodiversity and the Species Concept
• Varied Definitions
• Benefits of Biodiversity
• Threats to Biodiversity
• Natural and Human Caused Reductions
• Endangered Species Management
• ESA
• CITES
• Captive Breeding

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BIODIVERSITY AND THE SPECIES CONCEPT

• What is Biodiversity ?
• Genetic Diversity - Measures variety of different
  versions of same genes.
• Species Diversity - Measures number of different
  kinds of organisms within a community.
• Ecological Diversity - Measures richness and
  complexity of a community.

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What is Biodiversity ?

• Species Diversity
• Species Richness - Total number of species in a
  community.
• Species Evenness - Relative abundance of
  individuals within each species.

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What Are Species ?

• Species Definition
• Reproductive Isolation
• Genetic Species Concept
• DNA sequencing
• Evolutionary Species Concept
• Pluralistic Species Concept

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How Many Species Are There ?

• Currently 1.7 million species identified.
• Estimates range between 3-50 million.
• May be 30 million insect species.
• Invertebrates make up 70 of all known species,
  and probably most of yet to be discovered
  species.
• Tropical rainforests and coral reefs are
  biodiversity hotspots.
• NA and Europe only contain 10-15.

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Biodiversity Hotspots
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BENEFITS OF BIODIVERSITY

• Food
• As many as 80,000 edible wild plant species could
  be utilized by humans.
• Drugs and Medicines
• More than half of all prescriptions contain some
  natural product.
• Pharmaceutical companies actively prospect
  tropical countries for products.

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Benefits of Biodiversity

• Ecological Benefits
• Soil formation, waste disposal, air and water
  purification, nutrient cycling, solar energy
  absorption, and biogeochemical and hydrological
  cycles all depend on biodiversity.
• Can a system function without all its integral
  parts ?

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Benefits of Biodiversity

• Aesthetic and Cultural Benefits
• Cultural diversity inextricably linked to
  biodiversity.
• USFWS estimates Americans spend 104 billion
  annually on wildlife-related recreation.
• Ecotourism can be an important form of
  sustainable economic development.
• Existence (intrinsic) value.

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THREATS TO BIODIVERSITY

• Extinction - Elimination of a species.
• Natural Causes
• In undisturbed ecosystems, background rate
  appears to be one species per decade.
• In this century, human impacts have accelerated
  that rate, causing perhaps hundreds to thousands
  of extinctions annually.

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Natural Causes of Extinction

• Fossil record suggests more than 99 of all
  species ever in existence are now extinct.
• Most went extinct before humans arrived.
• End of Cretaceous - Dinosaurs and 50 of existing
  genera disappeared.
• Permian period - Two-thirds of all marine species
  and nearly half of all plant and animal families
  died out.

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Human-Caused Reductions in Biodiversity

• Habitat Destruction
• Biggest reason for current increase in extinction
  is habitat loss.
• Habitat fragmentation divides populations into
  isolated groups vulnerable to catastrophic
  events.
• Northern Spotted Owl

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Habitat Fragmentation
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Human-Caused Reductions in Biodiversity

• Invasive Species
• Invasive (exotic) organisms thrive in new
  territory where they are free of usual predators,
  diseases, or resource limitations that limited
  them in original habitat.
• Over past 300 years, approximately 50,000
  non-native species have become established in the
  U.S..
• At least 4,500 are free-living.
• 15 cause environmental damage.

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Human-Caused Reductions in Biodiversity

• Invasive Species
• Eurasian milfoil
• European green crab
• Cheatgrass
• Water hyacinth
• Kudzu vine
• Asian tiger mosquitoes
• Purple loosestrife
• Zebra muscles

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Invasive Species
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Human-Caused Reductions in Biodiversity

• Pollution
• Pesticides
• Lead
• Population
• Human population growth
• Resource Use
• Overharvesting
• American Passenger Pigeon
• Whales

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Human-Caused Reductions in Biodiversity

• Commercial Products and Live Specimens
• Wildlife smuggling is very profitable.
• Leopard fur / Rhinoceros horns
• U.S. Annual pet trade in wild species
• 2 million reptiles
• 1 million amphibians and mammals
• 500,000 birds
• 128,000,000 tropical fish
• Cyanide released above coral reefs.

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Human-Caused Reductions in Biodiversity
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Predator and Pest Control

• Many animal populations have been greatly reduced
  or exterminated because they are regarded as
  dangerous to humans or livestock.
• Animal control costs 20 million in federal and
  state funds annually.
• 700,000 birds and mammals annually.
• 100,000 coyotes

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ENDANGERED SPECIES MANAGEMENT

• Hunting and Fishing Laws
• By 1890s, most states had enacted some hunting
  and fishing laws.
• General idea was pragmatic, not aesthetic or
  moral preservation.
• In general, regulations have been extremely
  successful.

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Endangered Species Act

• Established in 1973.
• Endangered are those considered in imminent
  danger of extinction.
• Threatened are those likely to become endangered,
  at least locally, in the near future.
• Vulnerable are those that are naturally rare or
  have been locally depleted to a level that puts
  them at risk.

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Endangered Species Act

• ESA regulates a wide range of activities
  involving endangered species
• Taking (harassing, harming, pursuing, hunting,
  shooting, killing, capturing, or collecting)
  either accidentally, or on purpose.
• Selling
• Importing into or Exporting out of the U.S.
• Possessing
• Transporting or Shipping

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Endangered Species Act

• Currently, U.S. has 1,300 species on its
  Endangered and Threatened lists, and about 250
  candidate species waiting for consideration.
• Number reflects more about human interests than
  actual status.
• Invertebrates make up 75 of all species, but
  only 9 of T/E list.
• Listing process is extremely slow.

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Recovery Plans

• Once a species is listed, USFWS is required to
  propose a recovery plan detailing the rebuilding
  of the species to sustainable levels.
• Total cost of all current plans 5 billion.
• Some have been very successful.
• Opponents have continually tried to require
  economic costs and benefits be incorporated into
  planning.

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Private Land and Critical Habitat

• Eighty percent of habitat for more than half of
  all listed species is on non-public property.
• Supreme Court has ruled destroying habitat
  equates to taking.
• USFWS has been negotiating Habitat Conservation
  Plans (HCP) with private landowners.
• Landowners allowed to harvest resources as long
  as species benefit.

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Reauthorizing ESA

• ESA officially expired in 1992.
• Proposals for new ESA generally fall into two
  general categories
• Versions that encourage ecosystem and habitat
  protection rather than individual species.
• Safe harbor policies that allow exceptions to
  critical habitat designations.
• (Economic Considerations)

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Habitat Protection

• Latest management strategy is preservation of
  ecosystems supporting maximum biological
  diversity rather than species-by-species
  approach.
• Gap Analysis - Conservationists and wildlife
  managers look for unprotected landscapes that are
  rich in species.
• Broad-scale, holistic approach.

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International Wildlife Treaties

• Convention on International Trade In Endangered
  Species (CITES) - 1975.
• Regulated trade in living specimens and products
  derived from listed species.

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CAPTIVE BREEDING

• Breeding programs in zoos and botanical gardens
  are one method of saving threatened species.
• Repositories of genetic diversity.
• Most mammals in NA zoos are now produced from
  captive-breeding programs.
• Some zoos now participating in reintroduction
  programs.

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Captive Breeding

• Zoos have limited space for captive breeding.
• How many can / should we save ?
• Ultimate problem is that natural habitat may
  disappear while we are conserving the species
  itself.
• Another alternative is to attempt to save species
  in the wild.
• Provide funding for protection in native habitats.

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Summary

• Biodiversity and the Species Concept
• Varied Definitions
• Benefits of Biodiversity
• Threats to Biodiversity
• Natural and Human Caused Reductions
• Endangered Species Management
• ESA
• CITES
• Captive Breeding

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