1. Cycles That Occur in Nature

4. Water cycle  Moves between atmosphere, oceans & land  1 – water evaporates from the ocean  2 – water also evaporates from plants during the process of transpiration

5.  3 – The evaporated water then enters atmosphere as a gas (water vapor)  4 – Vapor condenses to form clouds  5 – when large enough, water will fall back to earth as precipitation

6.  6 – Water travels along the surface as runoff or seepage

7.  7 – Plants remove water by root uptake  Water is always equal in the cycle.  The amount never changes

8.  Concerns(due to humans)  Groundwater depletion due to irrigation  Unsafe drinking water due to pollution or animal waste. (causes 80% of diseases in undeveloped countries)

11. Carbon cycle Where is carbon stored?

12. Carbon cycle Where is carbon stored? In EVERY LIVING THING!!!!

13.  Photosynthesis: taken in by plants & converted to sugar

14.  Cellular Respiration: released

15.  Erosion & volcanoes: releases CO 2 in the air & ocean

16.  Decomposition: released (may be stored underground as fossil fuels)

17. Human Activities:  Mining  Burning fossil fuels  Cutting / burning down forests

20. Nitrogen cycle  Nitrogen –make up proteins and DNA  Where is most of it stored?  In the atmosphere!! (79%)  Plants and animals cannot take nitrogen from the atmosphere

21.  1. Bacteria converts nitrogen gas into ammonia in a process called:  nitrogen fixation.  2. A different bacteria converts ammonia into nitrates and nitrites needed by plants to make proteins  3. Plants take in nitrogen (as nitrates or nitrites)  4. Consumers get nitrogen by eating producers

22.  5. Organisms die, and return nitrogen to soil as ammonia

23.  6. Some ammonia taken up by producers  7. Nitrates are converted into nitrogen gas by bacteria in a process called denitrification  8. Nitrogen gas returns to the atmosphere

24.  Human activities can also add Nitrogen:  Use of fertilizers (travel by runoff)  Dumping raw sewage  Burning fossil fuels & wood  Leads to eutrophication (the end result is loss of oxygen from the water)

29. Phosphorus Cycle  1 – stored in rock (land & ocean floor) & soil  2 - Released by weathering & erosion  3 – travels in runoff

30.  4 – enters the ocean & gets used by some marine animals  5 – travels through the food web  6 – returned to soil through waste

31. Phosphorous Cycle 

33. Human Activities