Transcript Use of DDT - Lincoln-Sudbury Regional High School

Biodiversity &
Conservation Biology
Global biodiversity is threatened by
the extinction of more & more species
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Biodiversity is a measure of the number and
abundance of different species in a given area
Rapid extinction of species can reduce local and
global biodiversity irreversibly…why is this
important? What is the value of species
biodiversity?
Extinction is a natural
phenomenon
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What is so different about current
extinctions?
– Current rate of extinction is very high and
– Current rate of extinction is associated with
the behavior of just one species….yes, you
guessed it:
Humans!
The Global Biodiversity Crisis
Major threats to global biodiversity:
• habitat destruction
& pollution
• introduction of
non-native species
• over-exploitation
of wildlife
Habitat Alteration by Humans is the
Greatest Threat to Biodiversity
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Burning of rainforest
land to clear for
farming
Urban development
Strip Mining
Logging
Pollution: toxic waste
disposal, oil spills
Burning of fossil fuels
contributes to pollution
and Global Warming
Non-native Species Can Wreak
Havoc on Ecosystems
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The spread of Non-native (aka
Exotic or Alien) species has
increased as humans have
become more mobile
– In some cases the introduction of
an exotic species was done
deliberately, in others it has
occurred inadvertently
What is the story with
Cane Toads in Australia??!
Cane toads were introduced to Australia
from Hawaii in the 1930’s to control the
Cane Beetle, which was destroying the
Sugar Cane crop.
What happened?
Asian Longhorn Beetle has
arrived in Massachusetts!
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The Asian Longhorned Beetle (ALB) is an invasive pest from Asia that
came to the United States concealed in solid wood packing material (the
pallets and crates used to transport goods from overseas).
The ALB attacks and eventually kills American hardwoods, such as
maple, ash, birch, willow, poplar, and elm trees by boring into trunks
and branches during its larvae stage.
Early detection of infestations and rapid treatment response are crucial to
successful eradications of the beetle.
Human transport is a prime source of ALB infestation. So it is important to
refrain from moving wood out of ALB quarantine areas.
If the ALB were to become established here it could be one of the most
destructive and costly invasive species ever to enter the United States. It
threatens urban and suburban shade trees and recreational and forest
resources valued at hundreds of billions of dollars.
Quoted from: http://www.framinghamma.gov/index.aspx?NID=1343
Other Infamous “Aliens”
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Rabbits introduced to Australia by Brits,
for food and sport hunting (1859)
– Rabbits did what rabbits do… they multiplied
rapidly
– Overpopulation of rabbits ensued (no natural
predators in Australia) and vegetation became
overgrazed in many areas, leading to
desertification of grasslands
Overexploitation of Wildlife has
also accelerated extinctions
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Hunting of various species for sport and/or
profit has decimated several species to
dangerously low numbers…
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African Elephants (hunted esp. for ivory tusks)
Black Rhinoceroses (hunted for their horns)
Siberian Tigers (hunted for their fur & claws)
Whales (hunted for blubber/oil & meat)
U.S. Protection of Endangered
Species
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Endangered Species Act (1973): to protect plant
or animal species in danger of extinction
– Authorizes National Marine Fisheries Service (NMFS)
and US Fish & Wildlife Service (USFWS) to ID and list
all endangered & threatened species
– Prohibits catching or killing of protected animals,
prohibits uprooting of protected plants on Federal land.
Prohibits sale or trade of any part of a protected species
– Prohibits Federal Gov’t. from carrying out any project
that jeopardizes an endangered species
– Requires US Fish & Wildlife to prepare Recovery Plans
for all protected species
Hotspot Approach to Preserving Habitats
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A high priority of conservation efforts in the wild is the
identification & protection of sites with a high
concentration of species diversity
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Biodiversity
________
hotspots are the
most biologically
diverse areas of
the globe.
They usually have
a large number of
endemic species
(meaning they are
found nowhere
else in the world).