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OUR Ecological Footprint - 151. Live near work; Ride bike; minimize car use.2. Buy energy-efficient furnace.3. Programmable thermostat: winter/summer4. Turn off lights when leave room; unplug appliance5. Eat lower on food chain.6. Buy food locally; eliminate transportation energy.7. Buy hybrid car - reduce gas consumption by 1/28. Recycle; pay tax for it.9. Reduce paper/plastic (and ALL) consumption.10. Reuse (and repair) items; don’t use ‘throw- aways’11. Get ‘on demand’ water heater.12. Winterize house.13. Buy C offset for travel.
…for Tuesday
Go to: www.worldchanging.com
Select one article, read it, print first page (only) and bring to lecture.
1 Stuff 5 Business
2 Shelter 6 Politics
3 Cities 7 Planet
4 Community 8 Any of 1-7
OBJECTIVES
Human Activities Alter Nutrient Cycles Relates to Intersystem Cycles:
Inputs/Outputs disrupted-->consequences
• Water
• Carbon
• Nitrogen
• Ozone
• Phosphorus
• Sulfur
Intersystem cycling: Nutrients gained (input) and lost (output) by an ecosystem
Ecosystem 12
Input output
Ecosystem 2
Input
Output
Ecosystem 1
Nutrient inputs on land from:
• Lithosphere (weathering of bedrock and
soil)
• Atmosphere
– Wetfall (in precipitation)
– Dryfall (particles)
• Hydrosphere
• Human Activities
Nutrient losses (output) on land to:
• Atmosphere
• Streams and groundwater
• How do human activities alter output?
Global BGC cycles: Water cycle: a physical model
50% of water in the Amazon Basin is internally recycled. Predict how deforestation there might be affecting the hydrologic (water) cycle and the forest.
*
Figure 3
***Carbon cycle: What are 2 new fluxes due to human activities? What pools are being altered?
The missing C sink
Figure 6
How are humans altering the N cycle?• Nitrogen-fixing crops• Fossil fuel burning• Nitrogen fertilizer• Animal feed lots + manure • Invasive species fix N2• Consequences• greenhouse gases• nitrogen saturation• runoff - aquatic systems + water supply• biodiversity and species mix
Ozone (O3) + UV radiation
1. at surface
• O2 with NO2 with light --> O3
• NO2 from burning gas in cars
• Ozone = oxidant of organic molecules
• SOYFACE: elevated O3 lowers crop
productivity
• Human activities affect input from land to
water
• runoff/seepage into groundwater/aquifers
• agriculture land, especially NPK
• animal feedlots, especially N
• sewage input, C, N
Human eutrophication (overproduction of organic matter in aquatic systems) is harmful.
• Added nutrients stimulate algal GPP, BUT• • Too much overwhelms intrasystem regeneration• • Increase in organic matter; increased sediments• • Energy flows to bacteria, not higher trophic level• • Increase in decomposition + use of oxygen• ---> depletes oxygen• ---> kills aerobes, including fish
Consequences for aquatic systems
• change freshwater aquatic communities
• create ‘dead zones’ in oceans
• lower quality of drinking water
Effects of acid rain on a forest.Why is damage greater on 1 side of mt.?Why haven’t forests recovered when acid rain was lessened?
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