chapter 6 teacher notes - weebly
TRANSCRIPT
Chapter 6
Humans in the Biosphere
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6-1 A Changing Landscape
!● All organisms share Earth’s limited resources ● Understanding how humans interact with the
biosphere is crucial to protecting these resources
● Human activities that have changed the biosphere: hunting & gathering, agriculture, industry & urban development
6-2 Renewable & Nonrenewable Resources
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6-2 Renewable & Nonrenewable Resources
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Sustainable Use
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Land Resources
● land for cities & suburbs ● raw materials for industry ● food crops which grow best in fertile soil
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Sustainable Use Strategies
● contour plowing ● leave stems & roots from previous years
crops in place ● harvest mature trees selectively ● plant, manage, harvest and replant tree farms
in places where forests have already been cut ● Breed new, faster-growing tree varieties that
produce high quality wood
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Deforestation in the U.S.
• 2010- U.S. had 751,255,000 acres of forested lands
• Between 1990 and 2010 the U.S lost an average of 949,750 acres of forest each year and added 18,995,000 acres of forested land
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Ocean Resources
● major source of food/protein (fish) ● many species are being overfished ● approximately 2,215 species are listed as
endangered or threatened
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Air Resources
● Preserving air quality remains a challenge
Smog- Los Angeles California
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Acid Rain
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Water Resources
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Sustainable Use Strategies
● limit the catch of fish populations stressed by overfishing
● use technology to control emissions from factory smokestacks
● strict automobile emission standards ● clean air regulations ● protect natural systems involved in the water
cycle (wetlands) ● water conservation
6-3 Biodiversity “Species Richness”
The Value of Biodiversity • ecosystem stability • sources of food • provides us with medicine • provides us with industrial products • economic resources (eco-tourism)
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Biological Magnification
• widespread use of DDT (pesticide) threatened fish-eating birds with extinction (osprey, pelican & bald eagle)
• began showing up in the tissues of humans
• banned in the U.S in the early 1970’s
• bird populations have recovered
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!!!
Introduced/Invasive Species
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NYS Invasive Species
Emerald Ash BorerEurasian Milfoil
Purple Loosestrife
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Conserving Biodiversity
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6-4 Charting a Course for the Future
● Ozone Depletion ● Global Warming ● The Value of a Healthy Biosphere
Ozone Depletion
Ozone = Earth’s sunscreen
Main cause = CFC’s
Worldwide CFC production ended in the mid 1990’s
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Effects of Ozone Depletion
● skin cancer ● damage eyes (cataracts) ● decrease an organism’s resistance to disease ● damage tissue in plants & phytoplankton in
oceans
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Antarctic Ozone Hole
Global Warming/Climate Change
Global Emissions of Greenhouse Gases
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Melting of Arctic Sea Ice
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Effects of Global Warming
● ice melting worldwide (mountain glaciers, ice sheets covering Antarctica & Greenland, and Arctic Sea ice)
● rise in sea level ● animal and insect migration ● storms becoming stronger ● floods and droughts becoming more common ● less fresh water will be available ● spread of diseases like malaria ● ecosystems will change
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What Can We Do?
● reduce greenhouse gas emissions by burning less fossil fuels
● reduce energy consumption ● be energy efficient ● preserve and grow forests ● invest in new infrastructure ● upgrade existing highways and transmission
lines
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Hydrofracking
● large amounts of water combined with smaller amounts of chemicals and sand are pumped under high pressure into a drilled gas well
● this forces the rock to open up along tiny existing fractures allowing gas to flow more freely into the well
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Preserving Resources
1. Reduce: use less resources (walk rather than drive, use energy efficient appliances, etc.)
2. Reuse: use resources several times (use dishes instead of paper plates, etc.)
3. Recycle: use resources in a different product (recycle metal, plastic, glass)