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Nutrient Cycles. The magic of water What is a Nutrient? The Carbon cycle The Nitrogen cycle The Phosphorus cycle The Sulfur cycle. The Magic of Water. Life is watery! 60-70% by weight of living organisms Makes possible chemical reactions necessary for life Promotes neutrality. Polar.
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Nutrient Cycles • The magic of water • What is a Nutrient? • The Carbon cycle • The Nitrogen cycle • The Phosphorus cycle • The Sulfur cycle
The Magic of Water • Life is watery! • 60-70% by weight of living organisms • Makes possible chemical reactions necessary for life • Promotes neutrality
Polar 3
Extra OH- H+ + OH- = H2O Extra H+ CS Fig. 3.4 4
Least dense Most dense 5
Polarity 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?
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
C H O 8
Similar to CS Fig. 3.12 9
CS Fig. 3.13 10
Energy transfer in sample ecosystem Fig. 3.16
Biomass (with nutrients) transfer Fig. 3.17
Fig. 6.2 Biogeochemical Cycles = Natural +Anthropogenic ANTHROPOGENIC = HUMAN ORIGIN
ATMO- SPHERE SHORT TERM BIOTA 14
Millions to 100’s of Millions Years to Millenia Atmos- phere Biota Ocean Crust LONG-TERM CS Fig. 3.15 15 CS Fig. 3.20
Carbon Cycle (petagrams = 1015 grams) Natural sources = 207 Natural removals = 210 Anthropogenic sources = 6.4 – 7.4 Similar to CS Fig. 3.20
Nitrogen • Main reservoir is N2 in atmosphere • Cannot be used directly by plants • Necessary to build amino acids, peptides, proteins • DNA!
ATMOSPHERE ! BIOTA 18
Nitrogen made available for Life • N2 -> NO2- -> NO3- -> NH4+ -> Peptides and Proteins Or in words: • Gas – Nitrite – Nitrate – ammonium – organic molecules
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
Nitrogen Cycle (teragrams = 1012 grams) Eutrophication = The addition of excess nutrients to natural waters Anthropogenic = 170 - 445 Natural = 196 - 733 Similar to CS Fig. 3.21
Phosphorus • P necessary for • Nucleic acids • Cell membranes • Energy-transfer reactions • Bones • Teeth • Source: Minerals (soil)
CRUST BIOTA 23
NATURAL CYCLE BIOTA OCEAN CRUST
Phosphorus laid down as fertilizer more than what is delivered through Erosion!! CS Fig. 3.23
Sulfur • S important for proteins • Source: Minerals (soil)
Sulfur Cycle in 1012 moles Anthropogenic = Significant! Causes Acid Rain Similar to CS Fig. 3.24
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