1. Ecosystems and the Physical Environment Chapter 5

2. The Gaia Theory Dynamic Equilibrium Negative Feedback Positive Feedback

3. How Chemicals Cycle Biogeochemical Cycle The complete path a chemical takes through the three major components – or reservoirs – of Earth’s systems 1.Atmosphere 2.Hydrosphere 3.Lithosphere

4. Cycles Carbon 1.Lipids 2.Nucleic Acids 3.Carbohydrates 4.Amino Acids Nitrogen 1.Amino Acids Phosphorus 1.ATP 2.DNA 3. Cell Membranes Sulfur 1.Amino Acids 2.Keratin Fixed amounts of all elements on earth * Oxidation describes the loss of electrons by a molecule, atom or ion * Reduction describes the gain of electrons by a molecule, atom or ion

5. Carbon Cycle Billions of Tons http://www.youtube.com/watch?v= 0Vwa6qtEih8&feature=related

6. Carbon Silicate A weathering Cycle: 1.Atmospheric CO 2 forms H 2 CO 3 (Carbonic Acid) precipitation which moves through soil 2.H 2 CO 3 dissociates & forms H + & HCO - 3 (bicarbonate) 3.Silicate rich minerals interact with the free H + to release Ca 2+ 4.Shellfish 5.Subduction – silicate formation at temperatures above 300 °C

7. Carbon Silicate Believed to provide important negative feedback mechanisms that control the temperature of the atmosphere.

8. Nitrogen cycle Nitrogen cycle: Atmospheric nitrogen (N 2 ) Nitrogen fixation by humans Biological nitrogen 1. fixation 2. Nitrification NH 3 & NH 4 - NO 3 - 3. Assimilation 5.Denitrification Plant & animal proteins Decomposition - urea 4. Ammonification Internal cycling (Ammonia) Lightning Volcanoes Bacteria (Nitrates & Nitrites) (Oxidation) NO 3 - → NO 2 - → NO → N 2 O → N 2 gas

9. Nitrogen Cycle & Steps 1.Nitrogen Fixation is the conversion of elemental nitrogen(N 2 ) to organic ammonia(NH 3 ) by bacteria, lightning, industry, volcanoes. 2.Nitrification - conversion of ammonia or ammonium (NH 4 ) into nitrites(NO - 2 ) and then into nitrates (NO - 3 ) by bacteria 3.Assimilation- plants absorb nitrates or ammonia 4.Ammonification - nitrogen is converted into ammonia from animal waste or dead organisms by aerobic bacteria 5.Denitrification - anaerobic bacteria convert nitrates & nitrites to nitrogen gasses off to atmosphere 1.Nitrogen is not a reactive molecule 2.78% atmosphere N 2 & 21% oxygen &.038% CO 2 YouTube: http://www.youtube.com/watch?v=m4YToXw724w&feature=relatedhttp://www.youtube.com/watch?v=m4YToXw724w&feature=related

10. Phosphorus Cycle Does not include the atmosphere YouTube: http://www.youtube.com/watch?v=RKkC2JpjaGc&feature=related http://www.youtube.com/watch?v=RKkC2JpjaGc&feature=related

11. Phosphorus Cycle

12. Phosphorus Brazil

13. Guano

14. Accelerated Eutrophication

15. Cycling of Materials within Ecosystems Sulfur cycle: YouTube: http://www.youtube.co m/watch?v=BzPeA9oQ Nl8 http://www.youtube.co m/watch?v=BzPeA9oQ Nl8

17. Cycling of Materials within Ecosystems Hydrologic cycle:

18. Tectonic Cycle Tectonic cycle: Involves creation and destruction of the solid outer layer of Earth, the lithosphere Plate tectonics: The slow movement of these large segments of Earth’s outermost rock shell (7 plates) Boundaries between plates are geologically active areas

19. Internal Planetary Processes

20. Volcanic Activity 2011

21. Internal Planetary Processes Plate boundaries

22. Internal Planetary Processes Plate boundaries

23. Tectonic Cycle: Plate Boundaries Divergent plate boundary: New lithosphere is produced (seafloor spreading) Convergent plate boundary: Produces linear coastal mountain ranges or continental mountain ranges Transform fault boundary: San Andreas Fault in California

24. Internal Planetary Processes Volcanoes Most volcanoes occur along subduction zones

25. Internal Planetary Processes Volcanoes Some occur along spreading zones Few, such as Hawaiian Islands, not associated with plates.

26. Internal Planetary Processes Earthquakes caused by release of built up stress, typically along faults movement releases seismic waves Typical side effects include: 1) Landslides 2) Tsunamis