Transcript GEOL 1130 Nutrient Cycles

Nutrient Cycles
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The magic of water
What is a Nutrient?
The Carbon cycle
The Nitrogen cycle
The Phosphorus cycle
The Sulfur cycle
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The Magic of Water
• Life is watery!
– 60-70% by weight of living organisms
• Makes possible chemical reactions necessary for
life
• Promotes neutrality
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Polar
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Extra OH-
H+ + OH- = H2O
Extra H+
CS Fig. 3.4
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Least
dense
Most
dense
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The Magic of Water
• Life is watery!
• Makes possible chemical reactions
necessary for life
Polarity
• Promotes neutrality
• Sticks together
• Holds heat
• Large liquid temperature range
• Ice Floats!
• Evaporation provides cooling mechanism for organisms –
Did you remember your deodorant today?
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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
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C
H
O
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Similar to
CS Fig. 3.12
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CS Fig. 3.13
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Energy transfer in sample ecosystem
Fig. 3.16
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Biomass (with nutrients) transfer
Fig. 3.17
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Fig. 6.2
Biogeochemical
Cycles = Natural +
Anthropogenic
ANTHROPOGENIC =
HUMAN ORIGIN
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SHORT TERM
BIOTA
ATMOSPHERE
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Years to
Millenia
LONG-TERM
Atmosphere
Millions to
CS Fig.
100’s
of 3.15
Millions
Biota
Ocean
Crust
CS Fig. 3.20
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Carbon Cycle (petagrams = 1015 grams)
Natural sources = 207
Anthropogenic sources = 6.4 – 7.4
Natural removals = 210
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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!
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ATMOSPHERE
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BIOTA
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Nitrogen made available for Life
• N2 -> NO2- -> NO3- -> NH4+ -> Peptides and
Proteins
Or in words:
• Gas – Nitrite – Nitrate – ammonium – organic
molecules
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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
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Nitrogen Cycle (teragrams = 1012 grams)
Anthropogenic = 170 - 445
Natural = 196 - 733
Eutrophication =
The addition of
excess nutrients
to natural waters
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Similar to CS Fig. 3.21
Phosphorus
• P necessary for
– Nucleic acids
– Cell membranes
– Energy-transfer reactions
– Bones
– Teeth
• Source: Minerals (soil)
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CRUST
BIOTA
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NATURAL CYCLE
BIOTA
OCEAN
CRUST
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CS Fig. 3.23
Phosphorus laid down
as fertilizer more than
what is delivered through
Erosion!!
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Island of Nauru after mining for phosphorus
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Sulfur
• S important for proteins
• Source: Minerals (soil)
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Sulfur Cycle in 1012 moles
Anthropogenic = Significant!
Causes Acid Rain
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Similar to CS Fig. 3.24
The End.
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