1. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. ECOSYSTEMS: Cycles www.swpc.noaa.gov/

2. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Biochemical Cycling  Cycling of nutrients called biogeochemical cycling  Move nutrients from nonliving world to living organisms and back.  Without recycling, life could not exist  Four biogeochemical cycles –Carbon- Nitrogen –Oxygen- Phosphorus http://upload.wikimedia.org/wikipedia/commons/thumb/2/21/CNO_Cycle.svg/300px-CNO_Cycle.svg.png

3. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. http://www.kidsgeo.com/images/carbon-cycle.gif

4. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Carbon Cycling  Photosynthesis – removes carbon dioxide from the atmosphere and turns it into biomass.  Respiration – returns carbon dioxide to the atmosphere when food is burned by cells.  Carbon is also returned to the environment when an organism dies through the action of detrivores.

5. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Carbon Cycling  Some organisms die and accumulate.  Forms large layers of limestone rock –Store carbon in rocks for millions years  Known as carbon reservoir  Weathering returns carbon into atmosphere  Volcanic eruptions add carbon dioxide to atmosphere

6. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Carbon Cycling  Alternate path—plants and animals are buried  Exposed to heat and pressure beneath Earth’s surface  Causes chemical changes  Produces fossil fuels—oil and coal –Oil—once living plankton –Coal—remains of plants buried in swamps http://www.mii.org/Minerals/Minpics1/CoalAnthracite.jpg

7. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Carbon Cycling  Fossil fuels known as hydrocarbons  Composed of hydrogen and carbon  Burning returns to atmosphere as carbon dioxide http://www.ust.hk/~webpepa/pepa/ways_of_protection/air_general.JPG

8. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Carbon Cycling  Creation of methane gas (CH4)  Mud of rice paddies in Asia –Anaerobic bacteria release methane gas  Cows produce methane in their digestive systems. http://www.palacesandtigers.com/images/gallery/sri_lanka/Vil%20Uyana%20rice%20paddy.jpg

9. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

11. Oxygen Cycling  One of most important interactions –Photosynthesis and respiration reactions –Photosynthesis consumes carbon dioxide and releases oxygen  Used during respiration and carbon dioxide is released –Vital link between plants and animals on Earth www.rps.psu.edu

12. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Oxygen Cycling  The Earth’s crust is also a reservoir for oxygen storage. http://lasp.colorado.edu/~bagenal/3720/CLASS21/CO2cycle.jpg

13. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

15. Nitrogen Cycling - Nitrification  Begins with bacteria in soil and roots  Combine ammonia with other atoms  Nitrogen compounds absorbed by roots of plants  Used to make proteins http://www.thisland.uiuc.edu/50ways/images/5b.jpg

16. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Nitrogen Cycling - Nitrogen Fixation  Legumes harbor bacteria that fix nitrogen in small nodules in their roots.  Convert atmospheric nitrogen to plant-available nitrogen  Used to form proteins and other compounds, which makes nitrogen available to other organisms http://overton.tamu.edu/clover/cool/NodCrimW.jpg Nodules on Clover roots

17. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Nitrogen Cycling - Denitrification  Bacteria in the soil break down dead organisms, releasing nitrogen gas into the atmosphere. Denitrification filter, part of wastewater treatment plant. http://www.tampagov.net/dept_Wastewater/information_resources/Advanced_Wastewater_Treatment_Plant/Virtual_Tour/images/denit_filter.jpg

18. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

20. Phosphorus Cycling  Major source of phosphorus is not the atmosphere –Found in rocks  Phosphate-containing rocks become weathered (break down)  Main source of phosphorus for ecosystems of Earth http://content.answers.com/main/content/wp/en/thumb/b/b9/180px-PhosphateRockUSGOV.jpg

21. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Phosphorus Cycling  Animal wastes contain large amounts of phosphorus  Helps to recycle back through food chain  Rare in some ecosystems –Called a limiting factor http://www.gardening.cornell.edu/lawn/almanac/images/fertilizer3.gif

22. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. Phosphorus Cycling  Human activity raises phosphorus levels –Waste disposal and use of fertilizer  Causes rapid growth in aquatic plants and algae http://www.waterencyclopedia.com/images/wsci_01_img0017.jpg Result is algae bloom Chokes waterway with overgrowth

23. Copyright © 2008 Thomson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.