1. Cycles & Human Impacts

2. The Hydrologic Cycle

4. The Carbon Cycle

6. The Nitrogen Cycle

10. The Phosphorus Cycle

14. Understanding cycles provides a basis for determining how disturbances change ecosystems. In what ways are human interactions disturbing the hydrologic, carbon, nitrogen, phosphorus, and sulfur cycles?

15. Hydrologic Removal of large quanities for use in irrigation Removal of vegetation causes increased run off and less infiltration Excess nutrients (fertilizer/sewage) cause algal blooms, hypoxic conditions, & dead zones. Eutrophication! Carbon Fossil fuel combustion- releases C from rocks; adds CO 2 to atm & increased acidity of oceans Animal waste- adds CH 4 to atm Deforestation – less CO 2 removed from atm

16. Nitrogen Combustion NO x + H 2 0  HNO 3 in atmosphere Fertilizers- increases N into aquatic ecosystems and causes plant/nutrient pollution (eutrophication) Phosphorus Fertilizers, detergents- plant/nutrient pollution (eutrophication) Sulfur Coal combustion Smelting sulfide minerals Both of which result in So x exhaust + H20  H 2 SO 4 AMD

17. The N & P Cycles and Impacts on Aquatic Ecosystems Define nutrient. How do excess nutrients like nitrogen (and/or phosphorus) affect population sizes? How might a decrease in nutrients affect population sizes?

18. Eutrophication An aquatic ecosystem’s response to an influx of nutrients (N & P mostly). Leads to slow death of pond or lake

19. Eutrophication 1.Nutrients enter water 2.Algae “blooms”; limits Ps and decreases O 2 production 3.Algae die; Dead algae fall to bottom, begin decomposing 4.Decomposers consume O 2 breaking down dead algae 5.Other organisms “suffocate” from lack of oxygen  hypoxia

20. Eutrophication cwh.triplepointwater.com

21. Where do the excess N & P come from? Humans! Nutrients run off from lawns, farms, golf courses, etc… Nitrogen – Fertilizers – Livestock waste Phosphorus – Laundry detergents – Livestock waste

22. Eutrophication Video 1 http://uccpbank.k12hsn.org/courses/APEnviron mentalScience/course%20files/multimedia/less on78/animations/5a_Lake_Eutrophication.html

23. Eutrophication Videos 2 & 3 Montreal Lakes http://youtu.be/1svW3KSxjvc Barnegat Bay http://youtu.be/N_mY99MB3ew