Per. 4

‘ Fundamentals ’ of biogeochemical cycles
• All matter cycles...it is neither created nor destroyed...
• As the Earth is essentially a closed system with respect to matter, we can say that all matter on Earth cycles .
• Biogeochemical cycles: the movement (or cycling) of matter through a system

by matter we mean: elements (carbon, nitrogen, oxygen) or molecules (water) so the movement of matter (for example carbon) between these parts of the system is, practically speaking, a biogeochemical cycle
The Cycling Elements: macronutrients : required in relatively large amounts
"big six": carbon , hydrogen , oxygen , nitrogen , phosphorous sulfur

other macronutrients: potassium , calcium , iron , magnesium micronutrients : required in very small amounts, (but still necessary) boron (green plants) copper (some enzymes) molybdenum (nitrogen-fixing bacteria)

1. Which part of the atmosphere has the highest altitude?
A. Troposphere B. Stratosphere C. Thermosphere D. Mesosphere
2. Which part includes all three of the other parts?
Lithosphere B. Ecosphere C. Hydrosphere D. Atmosphere
3. Which one is not a major cycle?
A. Hydrogen B. Nitrogen C. Oxygen D. Sulfur E. Water

Condensation
Rain clouds
Precipitation
Precipitation to land
Runoff
Surface runoff
(rapid)
Transpiration
Transpiration from plants
Evaporation
Precipitation
Evaporation from land
Evaporation from ocean Precipitation to ocean
Infiltration and
Percolation
Surface runoff
(rapid)
Groundwater movement (slow)
Ocean storage
Figure 4-28
Page 76

1. Water withdrawal from streams, lakes and groundwater. (salt water intrusion and groundwater depletion)
2. Clear vegetation from land for agriculture, mining, road and building construction. (nonpoint source runoff carrying pollutants and reduced recharge of groundwater)
3. Degrade water quality by adding nutrients(NO
2
, NO
3
,
PO
4
) and destroying wetlands (natural filters).
4. Degrade water clarity by clearing vegetation and increasing soil erosion.

Diffusion between atmosphere and ocean
Combustion of fossil fuels
Carbon dioxide dissolved in ocean water photosynthesis aerobic respiration
Marine food webs
Producers, consumers, decomposers, detritivores incorporation into sediments death, sedimentation
Marine sediments, including formations with fossil fuels uplifting over geologic time sedimentation
Figure 4-29a
Page 78

volcanic action
Terrestrial rocks
Atmosphere
(most carbon is in carbon dioxide)
Combustion of fossil fuels photosynthesis aerobic respiration combustion of wood (for clearing land; or for fuel sedimentation weathering
Land food webs producers, consumers, decomposers, detritivores
Soil water
(dissolved carbon) leaching runoff death, burial, compaction over geologic time
Peat, fossil fuels
Figure 4-29b
Page 79

Natural Sources of
Carbon
Sources of Carbon from
Human Activity
•Death of plants and animals
•Animal waste
•Atmospheric CO2
•Weathering
•Methane gas from cows
(and other ruminants)
•Aerobic respiration from terrestrial and aquatic life
•Burning wood or forests
•Cars, trucks, planes
•Burning fossil fuels such as coal, oil and natural gas to produce heat and energy.

• Additional carbon is stored in the ocean.
• Many animals pull carbon from water to use in shells, etc.
• Animals die and carbon substances are deposited at the bottom of the ocean.
• Oceans contain earth ’ s largest store of carbon.

14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
1850
High projection
Low projection
1900 1950
Year
2000 2030 Figure 4-30
Page 79

1. What is no part of the water cycle?
A. Precipitation B. Percolation C. Transpiration D. Surface Runoff
E. Boiling
2. Which is not a man made way of adding carbon to the carbon cycle?
A. Airplanes B. Natural Fires C. Cars D. Burning fossil fuels
3. What are the predictions for how much carbon will be added from fossil fuels?
A. Low B. Medium-Low C. Medium D. High

• Lightning
• Inorganic fertilizers
• Nitrogen Fixation
• Animal Residues
• Crop residues
• Organic fertilizers

• Urea  CO(NH
2
)
2
• Ammonia  NH
3
(gaseous)
• Ammonium  NH
4
• Nitrate  NO
3
• Nitrite  NO
2
• Atmospheric Dinitrogen  N
2
• Organic N

Nitrogen
Reservoir
Atmosphere
Ocean  soluble salts
Biomass
Metric tons nitrogen
3.9*10 15
6.9*10 11
5.2*10 8
Actively cycled
No
Yes
Yes
Land  organic matter
 Biota
1.1*10 11
2.5*10 10
Slow
Yes

• Plants and bacteria use nitrogen in the form of NH
4
+ or NO
3
-
• It serves as an electron acceptor in anaerobic environment
• Nitrogen is often the most limiting nutrient in soil and water.

• amino acids
• nucleic acids (purine, pyrimidine)
• cell wall components of bacteria (NAM).

• Ammonification/mineralization
• Immobilization
• Nitrogen Fixation
• Nitrification
• Denitrification

N
2
N
2
O
NH
4
NO
NO
2
R-NH
2
NO
2
NO
3

Which of the following is not part of the Nitrogen Cycle?
A) Ammonification
B) Nitrification
C) Denitrosation
D) Nitrogen Fixation
E) Denitrification
In what form(s) do plants and bacteria use nitrogen?
A) NH
4
+
B) NH
3
C) NO
3
-
D) A and C
E) All of the above
What is the molecular formula for ammonium?
A) NH
4
+
B) NH
3
C) NO
3
D) NO
2
E) none of the above

N
2
N
2
O
NH
4
NO
2
R-NH
2
NO
NO
2 NO
3

• Decomposers: earthworms, termites, slugs, snails, bacteria, and fungi
• Uses extracellular enzymes  initiate degradation of plant polymers
• Microorganisms uses:
• Proteases, lysozymes, nucleases to degrade nitrogen containing molecules

• Plants die or bacterial cells lyse  release of organic nitrogen
• Organic nitrogen is converted to inorganic nitrogen (NH
3
)
• When pH<7.5, converted rapidly to NH
4
• Example:
Urea NH
3
+ 2 CO
2

• The opposite of mineralization
• Happens when nitrogen is limiting in the environment
• Nitrogen limitation is governed by C/N ratio
• C/N typical for soil microbial biomass is 20
• C/N < 20  Mineralization
• C/N > 20  Immobilization

N
2
N
2
O
NH
4
NO
2
R-NH
2
NO
NO
2 NO
3

• Energy intensive process :
• N
2
+ 8H+ + 8e + 16 ATP = 2NH
16ADP + 16 Pi
3
+ H
2
+
• Performed only by selected bacteria and actinomycetes
• Performed in nitrogen fixing crops
(ex: soybeans)

• Azobacter
• Beijerinckia
• Azospirillum
• Clostridium
• Cyanobacteria
• Require the enzyme nitrogenase
• Inhibited by oxygen
• Inhibited by ammonia (end product)

N
2 fixing system Nitrogen Fixation (kg
N/hect/year)
Rhizobium-legume 200-300
Cyanobacteria- moss 30-40
2-25 Rhizosphere associations
Free- living 1-2

Immobilization is the opposite of which process in the cycle?
A) Mineralization
B) Nitrification
C) Immobilization
D) Nitrogen Fixation
E) Denitrification
What process takes place when nitrogen is limiting in the environment?
A) Mineralization
B) Nitrification
C) Immobilization
D) Nitrogen Fixation
E) Denitrification
Which has the highest rate of nitrogen fixation?
A) Rhizobium-legume
B) Cynaobacteria-moss
C) Rhizosphere associations
D) Free-living
E) Azobacter

• Occur in overlying waters
• Aerobic soil
• Anaerobic soil
• Oxidized rhizosphere
• Leaf or stem surfaces of plants

• Occurs mostly in salt marshes
• Is absent from low pH peat of northern bogs
• Cyanobacteria found in waterlogged soils

N
2
N
2
O
NH
4
R-NH
2
NO
NO
2
NO
2
NO
3

Two step reactions that occur together :
• 1 rst step catalyzed by Nitrosomonas
2 NH
4
+ + 3 O
2
 2 NO
2
+2 H
2
O+ 4 H +
• 2 nd step catalyzed by Nitrobacter
• 2 NO
2
-
+ O
2
 2 NO
3
-

• Optimal pH is between 6.6-8.0
• If pH < 6.0  rate is slowed
• If pH < 4.5  reaction is inhibited
In which type of wetlands do you thing Nitrification occurs?

N
2
N
2
O
NH
4
NO
2
R-NH
2
NO
NO
2 NO
3

• Removes a limiting nutrient from the environment
• 4NO
3
-
+ C
6
H
12
• Inhibited by O
2
O
6
 2N
2
+ 6 H
• Not inhibited by ammonia
2
0
• Microbial reaction
• Nitrate is the terminal electron acceptor

4

Denitrication is inhibited by
A) NH
3
B) NH
4
+
C) NO
2
-
D) O
2
The second step of Nitrification is catalyzed by
A) Nitrosomonas
B) Clostridium
C) Azobacter
D) Nitrobacter
E) Beijerinckia
Which pH is within the optimal range for nitrication?
A) 1.5
B) 4.6
C) 7.1
D) 8.7
E) 10.9

Surfac e water
Oxidized layer
Reduce d soil layer
Low
[NH
4
]
[NH
4
]
HIGH
Slow Diffusion
Biodegradati on
C/N <20
C/N >20

Surfac e water
Oxidized layer
Reduce d soil layer
Low
[NH
4
] nitrificatio n
[NH
4
]
HIGH
Slow Diffusion
[NO
3
] high

Surfac e water
Oxidized layer
Reduce d soil layer
N
2
[NO
3
] high
Leaching
[NO
3
] Low
Denitrification

FERTILIZER
GUANO weathering agriculture uptake by autotrophs uptake by autotrophs
MARINE
FOOD
WEBS
DISSOLVED
IN OCEAN
WATER death, decomposition sedimentation settling out
MARINE SEDIMENTS leaching, runoff DISSOLVED IN
SOIL WATER,
LAKES, RIVERS death, decomposition
LAND
FOOD
WEBS weathering uplifting over geologic time
ROCKS
Figure 4-33
Page 82

1. Humans mine LARGE quantities of phosphate rock to use in commercial fertilizers and detergents. Phosphorous is NOT found as a gas, only as a solid in the earth
’ s crust. It takes millions to hundreds of millions of years to replenish.
2. Phosphorous is held in the tissue of the trees and vegetation, not in the soil and as we deforest the land, we remove the ability for phosphorous to replenish globally in ecosystems.
3. Cultural eutrophication – ad excess phosphate to aquatic ecosystems in runoff of animal wastes from livestock feedlots, runoff of commercial phosphate fertilizers fro cropland, and discharge of municipal sewage.

• 1.Phosphorous is an essential nutrient of both plants and animals.
• 2. It is part of DNA molecules which carry genetic information.
• 3. It is part of ATP and ADP) that store chemical energy for use by organisms in cellular respiration.
• 4. Forms phospholipids in cell membranes of plants and animal cells.
• 5. Forms bones, teeth, and shells of animals as calcium phosphate compounds.

Sulfur dioxide
Sulfur trioxide
Oxygen
Water
Sulfuric acid
Ammonia
Hydrogen sulfide
Dimethyl sulfide
Volcano
Industries
Animals
Ammonium sulfate
Plants
Acidic fog and precipitation
Ocean
Sulfate salts
Metallic sulfide deposits
Decaying matter
Sulfur
Hydrogen sulfide
Figure 4-34
Page 83

Approximately 1/3 of all sulfur emitted into atmosphere comes from human activities.
• 1. Burning sulfur containing coal and oil to produce electric power (SOx = acid deposition).
• 2. Refining petroleum – (SOx emissions)
• 3. Smelting to convert sulfur compounds of metallic minerals into free metals (Cu, Pb, Zn)
• 4. Industrial processing.

1. Sulfur is a component of most proteins and some vitamins.
2. Sulfate ions (SO
4
2) dissolved in water are common in plant tissue. They are part of sulfur-containing amino acids that are the building blocks for proteins.
3. Sulfur bonds give the three dimensional structure of amino acids.
4. Many animals, including humans, depend on plants for sulfur-containing amino acids.

The Oxygen cycle

1. The Phosphorus Cycle takes
A. Short time B. 20 years to fully cycle through C. 100 years to cycle through D. Geological Timescal
2. What percentage of sulfur is emmited buy human activity?
A. .01% B. 20% C. 33.3% D. 66.7% E. Over 90%
3. The vast majority of oxygen in the ecosphere is in
A. Outer space B. Lithosphere C. Atmosphere D. Hydrosphere

Photosynthesis: occurs within the chloroplasts of green plants.
The photosynthetic membranes are arranged in flattened sacs called the thylakoids.
6CO
2
+ 12H
2
O C
6
H
12
O
6 light
+ 6O
2
+ 6H
2
O
(reactants)
Function: Chemical energy
(products)
Storage for cell use

Cellular Respiration occurs in light simultaneously with photosynthesis. It occurs in the cytoplasm and mitochondria.
It is the reverse reaction of photosynthesis.
Function = chemical energy release
C
6
H
12
O
6
+ 6O
2
+ 6H
2
O 6CO
2
+ 12H
2
O+ chemical energy
(reactants) (products)

• Gross Primary Productivity (GPP) – the rate at which an ecosystem ’ s producers capture and store a given amount of chemical energy as biomass in a given period of time.
• Net Primary Productivity (NPP) – the rate at which all the plants in an ecosystem produce net useful energy; equal to the difference between energy produced through photosynthesis and energy used for cellular respiration.

• Eutrophication : natural process; over
1000 ’ s of years, lakes fill in with sediment, become marshes then dry land
• Cultural Eutrophication : same process, but speeded enormously by loading with “ limiting nutrients ”
(typically P, sometimes N)

• 1. Humans are excavating minerals and removing rock material. It takes millions of years for rock to form.
• 2. Humans remove sediments for building materials. This removes sediments that may form sedimentary rocks in the future.
• 3. Humans are filling in wetlands (peatlands), area that will form future coal beds.

1. Which part of the atmosphere is the ozone layer right above?
A. Stratosphere B. Troposphere C. Mesosphere D. Thermosphere
2. How long does it take rock formations to form?
A. 1,000 years B. 10,000 years C. 100,000 years D. 1,000,000 years E.
10,000,000 years
3. What is cultural eutrophication good for?
A. Fish B. Dissolved Oxygen in the lake C. algae D. clear lake

1.
http://science.pppst.com/carboncycle.html
2. westernreservepublicmedia.org/earthmotion3/image s/Carbon_Cycle.ppt
3. clima-dods.ictp.it/d3/annalisa/ocean_sv/lecture1.ppt
4. www.geology.wmich.edu/Koretsky/envs2150/Pcycl e_1.ppt