Download WFSC 420 Chapter 11

Biological Wealth
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Goods and services provided by
biodiversity.
~$38 Trillion per year
Examples of Goods and Services
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Gas, climate, and water regulation
Water supply
Erosion control
Soil formation
Pollination
Biological Wealth = $38 Trillion/Year
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Biological control
Food production
Recreation
Raw materials
Nutrient cycling
Waste treatment
Two Kinds of Value
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Instrumental: beneficial to humans
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Sources for agriculture, forestry, aquaculture,
and animal husbandry
Recreational, aesthetic, and scientific value
Sources of medicine
Intrinsic: value for its own sake
Source for Agriculture: Wild or Cultivated?
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Highly adaptable to changing
environments
Have numerous traits for resistance
Lack genetic vigor
Source for Agriculture: Wild or Cultivated?
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High degree of genetic diversity
Represents the genetic bank
Need highly controlled environmental
conditions
High degree of genetic diversity
Need highly controlled environmental
conditions
Sources for Medicine: Vincristine
Sources of Medicine
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Vincristine from rosy periwinkle cures leukemia.
Capoten from the venom of the Brazilian viper
controls high blood pressure.
Taxol from the bark of the pacific yew used to
treat ovarian, breast, and small-cell cancers.
Recreational, Aesthetic, and Scientific Value
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Ecotourism: largest foreign exchangegenerating enterprise in many developing
countries
$104 billion spent on wildlife-related
recreation
$31 billion spent to observe, feed, or
photograph wildlife
Intrinsic Value
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Value for Their Own Sake.
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Why?
Philosophical/Moral issue.
Not a scientific issue.
Saving Wild Species
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Game animals in the United States
Acts protecting endangered species
Past Wildlife Management Problems
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Restoring the numbers of many game
animals, e.g., deer, elk, turkey
Passing laws to control the collection and
commercial exploitation of wildlife
Poaching and over hunting
Contemporary Wildlife Management
Problems
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Road-killed animals
Population explosion of urban wildlife
Lack of natural predators
Wildlife as vectors for certain diseases
Pet predation by coyotes
Changed societal attitudes towards animals
Acts Protecting Endangered Species
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Lacey Act: forbids interstate commerce of
illegally killed wildlife
Endangered Species Act (ESA): protects
endangered and threatened species
Species at Risk: United States
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Total endangered U.S. species = 987 (388
animals, 599 plants)
Threatened U.S. species = 276 (129
animals, 147 plants)
The Status of U.S. Species
Causes of Animal Extinctions
Reasons for Biodiversity Decline
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Habitat alterations
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Conversions
Fragmentation
Simplification
Reasons for Biodiversity Decline
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Pollution
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Examples
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Acid Rain
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Caused by combustion of fossil fuels
10% of lakes in eastern US affected
DDT
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DDT used to kill insect pests
Biological amplification causes high levels in secondary
and tertiary consumers
 Causes fragile shells in predatory birds
 Decline in Bald Eagle, Osprey, Peregrine Falcon etc…
Reasons for Biodiversity Decline
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Introduction of exotic species, e.g.,
Starling, House Sparrow, Oriental
Bittersweet, Multiflora Rose etc…
Reasons for Biodiversity Decline:
Human Population Growth
Reasons for Biodiversity Decline:
Overuse
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Examples
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Harvest of 50 million songbirds for food –
Southern Europe
Trafficking in wildlife and products derived
from wild species – $10 billion/year
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90% decline in rhinos
1.6 tons of tiger bones = 340 tigers
Parrot smuggling: 40 of 330 species face extinction
What steps should we take to reduce
biodiversity decline?
Birds of Prey
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Bald Eagle
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Considered threatened by 1921
Extinct in North East by 1937
First use of DDT – 1943 to kill lice in Europe
and in US army
Extensive use in nature started ~1955, peaked
in 1962
Biological Amplification
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DDT is fat soluble
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Cannot be flushed out of body
Accumulates in tissues
Organisms high on the food chain most
effected