1. Why is it important that nutrients cycle?
Agenda for Tuesday Jan 17th
Cycles notes

2. Cycles in Earth Law of Conservation of Mass
Biogeochemical cycles – exchange of matter through biosphere
Reservoirs/sinks – places where matter & nutrients stored

4. Water Cycle Evaporation – liquid water becomes a gas
Transpiration – evaporating off plants
Condensation – water changing from gas to liquid

5. 3. Precipitation – water falling to Earth from atmosphere
4. Run-off – water running over the land
collect in the oceans, lakes or rivers
5. Infiltration – water seeping into the ground
Ground Water- stored in underground caverns and porous rock
Provides water for the soil, streams, rivers, and oceans

7. Human impacts on water cycle
Removing forests and vegetation – increases runoff and erosion, reduces transpiration and lowers water tables
Damming rivers increases evaporation and infiltration
Emitting pollutants = acid precipitation
Most threatening : overdrawing groundwater
Agriculture, watering, etc.
Lake Mead
White Bear Lake 7 7

8. What is transpiration? Agenda for Wednesday Jan 18th Carbon cycle
Human affects of carbon cycle activity

9. Carbon and Oxygen Cycles

10. Where is the carbon? Stored in oceans, plants, air Fossil fuels
Many animals pull carbon from water to use in shells, etc.
Oceans contain earth’s largest store of carbon
Photosynthesis – plants
Fossil fuels
Oil, coal, natural gas

11. Ways carbon moves Photosynthesis – moves from environment to plants
6 CO2 + 6 H2O C6H O2
Respiration- moves from living things back to the environment
Decomposition/Decay- moving from dead organisms back to the environment
Combustion- Burning releases carbon back into the atmosphere
Sunlight

12. Carbon Movement
Photosynthesis

14. Carbon in the Atmosphere
Greenhouse effect
Trapping of heat by molecules (water, methane, CO2,)

16. Human Impact Fossil fuels
Releases stores of carbon
Burning anything releases more carbon into atmosphere
Deforestation and Habitat Destruction
Fewer plants mean less CO2 removed from atmosphere
Methane release
Agriculture and animal, wetlands, leakages during natural gas extraction, transportation, use

17. Humans affect the carbon cycle
Today’s atmospheric carbon dioxide reservoir is the largest in the past 800,000 years

18. Photo from IPCC

19. The Keeling Curve

20. Effects of Climate Change
Ecosystem change
Ranges being shifted
Some butterflies, foxes, and alpine plants have moved farther north or to higher, cooler areas
Flowering earlier
Loss of species
Polar Bears, penguins, golden toad
Climate Change: marine ecosystems

21. Why artic sea ice matters It reflects sunlight
Glaciers are melting
Why artic sea ice matters
It reflects sunlight
It influences ocean and air currents
Keeps methane locked away
It limits severe weather
It supports native people and wildlife
IPCC (2007) 21

22. Other Effects Sea Level Rise Spread of diseases
Melting of ice sheets
Expansion of heated (warm) sea water
Flooding of coastal communities
Spread of diseases
Increase of extreme weather events
Precipitation (rain and snowfall) has increased across the globe, on average

23. Nitrogen Cycle Nitrogen is found in atmosphere and is unusable
Nitrogen is used for proteins, DNA
Nitrogen is found in atmosphere and is unusable
Converted to a useable form through nitrogen fixation
Special organisms/bacteria that convert
legumes
Lightning
Animals get nitrogen from eating plants
Returned to soil when animals urinates/dies
Denitrification – nitrogen is converted back to gas

25. Humans affect the nitrogen cycle
Fertilizer
animal waste
Excess Nitrogen can cause Eutrophication
causes aquatic life to die due to low levels of oxygen

26. Decreasing Nitrogen Pollution
Decrease fertilizer use
Using new farming methods
MN Buffer law
Maintaining wetlands