"CHONPS"
system/model

Nutrient,
Element		 Biological
Form		 Abiotic
Source for Humans		 Largest Abiotic
Reservoir		 Human
Impact
Carbon C all Organic Compounds
all Biopolymers		 Atm. CO2
720x109 mTons		 Lithosphere CaCO3
1x1017 mTons		 Atm. CO2 incr.
1% 8x109 mTon/yr
Nitrogen N Proteins, DNA, other Atmosphere N2
4x1015 mTons 		Lithosphere
2x1017 mTons 		N fixation & burning
4.2% 13x107 mTons/yr
Phosphorus P DNA, ATP, cell membranes Lithosphere
2x1016 mTons		 Lithosphere
2x1016 mTons		 Mining fertilizer
8.8% 5x107 mTons/yr
Sulfur S Amino Acids Lithosphere
4x109 mTons		 Lithosphere
4x109 mTons		 Mining fertl. & fossil fuels
17% 12x107 mTons/yr
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Biogeochemical cycles--types



      • Nutrients are included in these cycles: (C,H,O,N,P,S)

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      Which is the largest reservoir?
      What is the human impact ?

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      Bacteria Rule the Nitrogen Cycle
      Which is the largest reservoir?
      How large is the human impact ?

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      Direct human use of largest
        reservoirs: P & S
      How large is the human impact ?


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      How large is the human impact ?

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LIMITING NUTRIENTS

        Leibig's Law of the Minimum

        Q. Why is N commonly a limiting nutrient in terrestrial ecosystems?

        A. Ammonium and nitrate ions are highly soluble in water and easily leached from the soil

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