1. 1 Nutrient Cycles The magic of water What is a Nutrient? The Carbon cycle The Nitrogen cycle The Phosphorus cycle The Sulfur cycle

2. 2 The Magic of Water Life is watery! –60-70% by weight of living organisms Makes possible chemical reactions necessary for life Promotes neutrality

3. 3 3 Polar

4. 4 4 CS Fig. 3.4 Extra H + Extra OH - H + + OH - = H 2 O

5. 5 5 Most dense Least dense

6. 6 The Magic of Water Life is watery! Makes possible chemical reactions necessary for life Promotes neutrality Sticks together Holds heat Large liquid temperature range Ice Floats! Evaporation provides cooling mechanism for organisms – Did you remember your deodorant today? Polarity

7. 7 What are Nutrients? Elements used as building blocks in organic compounds needed to build living cells C. HOPKINS More basic than vitamins! These are the things vitamins are made of

8. 8 8 C H O

9. 9 9 Similar to CS Fig. 3.12

10. 10 CS Fig. 3.13

11. 11 Energy transfer in sample ecosystem Fig. 3.16

12. 12 Biomass (with nutrients) transfer Fig. 3.17

13. 13 Fig. 6.2 Biogeochemical Cycles = Natural + Anthropogenic ANTHROPOGENIC = HUMAN ORIGIN

14. 14 ATMO- SPHERE BIOTA SHORT TERM

15. 15 CS Fig. 3.15 Crust Atmos- phere Biota Years to Millenia Millions to 100’s of Millions CS Fig. 3.20 LONG-TERM Ocean

16. 16 Carbon Cycle (petagrams = 10 15 grams) Anthropogenic sources = 6.4 – 7.4 Natural sources = 207 Natural removals = 210 Similar to CS Fig. 3.20

17. 17 Nitrogen Main reservoir is N 2 in atmosphere – Cannot be used directly by plants Necessary to build amino acids, peptides, proteins DNA!

18. 18 ATMOSPHERE BIOTA !

19. 19 Nitrogen made available for Life N 2 -> NO 2 - -> NO 3 - -> NH 4 + -> Peptides and Proteins Or in words: Gas – Nitrite – Nitrate – ammonium – organic molecules

20. 20 Case Study: Why trees need salmon; pg 52 Bears feasting on salmon leave about half of carcass in woods –Scavengers and bears deposit up to 120 kg of N/hectare Similar to fertilizer quantities added to forest plantations Nitrogen important nutrient for trees –In good salmon years, rainforest trees grow up to three times as fast Forest ecosystem needs stream ecosystem and stream ecosystem needs forest ecosystems –Implications for salmon management? Most stocks down 90% and some gone

21. 21 Nitrogen Cycle (teragrams = 10 12 grams) Eutrophication = The addition of excess nutrients to natural waters Natural = 196 - 733 Anthropogenic = 170 - 445 Similar to CS Fig. 3.21

22. 22 Phosphorus P necessary for –Nucleic acids –Cell membranes –Energy-transfer reactions –Bones –Teeth Source: Minerals (soil)

23. 23 CRUST BIOTA

24. 24 CRUST BIOTA OCEAN NATURAL CYCLE

25. 25 CS Fig. 3.23 Phosphorus laid down as fertilizer more than what is delivered through Erosion!!

26. 26 Island of Nauru after mining for phosphorus

27. 27 Sulfur S important for proteins Source: Minerals (soil)

28. 28 Sulfur Cycle in 10 12 moles Anthropogenic = Significant! Causes Acid Rain Similar to CS Fig. 3.24

29. 29 The End. Back