Transcript What have we done!

What have we done!
Impact of ecology as a science
• Ecology provides a scientific context for
evaluating
environmental issues
– Rachel Carson, in 1962,
in her book, Silent Spring,
warned that use of
pesticides such as DDT
was causing population
declines in many
non-target organisms
Barry Commoner’s Laws of Ecology
• Everything is connected to everything else
• Everything must go somewhere
 there is no such place as “away”
• Nature knows best
• There is no such thing as a free lunch
Laws of Unintended Consequences
Acid Precipitation nitrogen oxides
 sulfur dioxide
• power plants
• industry
• transportation
Acid rain
BioMagnificatin
BioMagnificatin
• PCBs
– General Electric
manufacturing
plant on Hudson
River
– PCBs in sediment
– striped bass
nesting areas
Carbon
Dioxide
Global
Warming
CO2
NOx
methane
Ozone
Depletion
protects from
UV rays
Ozone
Depletion
Ozone Depletion
• Loss of ozone above Antarctica
Bad ozone vs. good ozone
Deforestatio
n
• Loss of habitat
• Loss of biodiversity
Loss of Diversity
• 3 levels of biodiversity
– ecosystem diversity
• different habitats across
landscape
– community diversity
• mix of species
– genetic diversity
• inbreeding with
shrinking populations
• All decreased by
human activity
Driven to extinction
Introduced species
• Introduced species
– transplanted populations grow
exponentially in new area
– non-native species
out-compete native species
• lack of competitors & predators
• reduce diversity
– examples
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African honeybee
gypsy moth
zebra mussel
purple loosestrife
gypsy moth
kudzu
Zebra
mussel
~2 months
Purple loosestrife