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Biogeochemical Cycles

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Lithification. Weathering & Volcanism. Dissolution. Photosynthesis. Burial & Lithification. Exsolution. Carbon Cycle. Atmosphere. Hydrosphere. Lithosphere. Biosphere ... – PowerPoint PPT presentation

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Title: Biogeochemical Cycles


1
Biogeochemical Cycles
  • Energy Flow through and Nutrient Cycling in
    Ecosystems

2
http//soils.usda.gov/sqi/SoilBiology/soil_food_we
b.htm
3
Biogeochemical CyclesReservoirs Pathways
Atmosphere
Biosphere
Lithosphere
Hydrosphere
4
Some Major Cycles of Matter
  • Water Cycle
  • Rock Cycle
  • Chemical Cycles
  • Carbon
  • Nitrogen
  • Phosphorous
  • Sulfur

5
Nutrient Cycles
Cycling maintains homeostasis (balance) in the
environment.
6
  • Water cycle-
  • Evaporation, transpiration, condensation,
    precipitation

7
Water cycle-
8
  • Carbon cycle-
  • Photosynthesis and respiration cycle carbon and
    oxygen through the environment.

9
Carbon cycle-
10
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11
Nitrogen cycle-
  • Atmospheric nitrogen (N2) makes up nearly 78-80
    of air.
  • Organisms can not use it in that form.
  • Lightning and bacteria convert nitrogen into
    usable forms.

12
Nitrogen Cycle
  • Only in certain bacteria and industrial
    technologies can fix nitrogen.
  • Nitrogen fixation-convert atmospheric nitrogen
    (N2) into ammonium (NH4) which can be used to
    make organic compounds like amino acids.
  • N2 NH4

13
Nitrogen cycle Nitrogen-fixing bacteria Some
live in a symbiotic relationship with plants of
the legume family (e.g., soybeans, clover,
peanuts).
14
  • Nitrogen cycle
  • Some nitrogen-fixing bacteria live free in the
    soil.
  • Nitrogen-fixing cyanobacteria are essential to
    maintaining the fertility of semi-aquatic
    environments like rice paddies.

15
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16
N movement in a watershed
Precipitation, NO3, NH3
Watershed View of Nitrogen Transport Use
Nitrogen Fixation
N
NO3 NH3
  • NO3- ions relatively mobile-washes N out of
    terrestrial environment
  • In pristine environment, most nitrogen moves as
    DON (dissolved organic N)

17
Nitrogen Cycle
Atmospheric nitrogen
Lightning
Denitrification by bacteria
Animals
Nitrogen fixing bacteria
Plants
Decomposers
Nitrification by bacteria
Nitrites
Nitrates
Ammonium
18
Bio-concentration
19
Bioconcentrationup the Trophic Pyramid
Energy degrades
but matter does not
Toxin (e.g. heavy metals)
20
  • Toxins in food chains-
  • While energy decreases as it moves up the food
    chain, toxins increase in potency.
  • This is called biological magnification

Ex DDT Bald Eagles
21
Carbon Cycle
Atmosphere
Biosphere
Lithosphere
Hydrosphere
22
Carbon TransferBiosphere Atmosphere
Photosynthesis (Atmosphere to Biosphere)
Carbon Dioxide Water Sunlight --gt Sugar
Oxygen
Respiration (Biosphere to Atmosphere)
Sugar Oxygen --gt Carbon Dioxide Water Energy
23
Carbon Cycle
Atmosphere
Biosphere
Lithosphere
Hydrosphere
24
Carbon Cycle
Human Impacts
Atmosphere
Biosphere
Net Effect Increase in Carbon in Atmosphere
Lithosphere
Hydrosphere
25
Nitrogen Cycle
Atmosphere
Denitification bacteria
Biosphere
  • Nitrogen fixation
  • bacteria
  • lightning

Absorption
Waste Decomposition
Erosion
Lithosphere
Hydrosphere
26
Nitrogen Cycle
Human Impacts
Atmosphere
Biosphere
Net Effect Increase in Nitrogen in water soil
  • Nitrogen fixation
  • industrial (fertilizer)
  • combustion

Increased Erosion
Lithosphere
Hydrosphere
27
Phosphorous Cycle
Never enters the atmosphere
Atmosphere
Biosphere
Absorption
Waste Decomposition
Weathering Erosion
Lithosphere
Hydrosphere
Absorption
Sedimentation
28
Phosphorous Cycle
Human Impacts
Biosphere
Net Effect Increase in phosphorous in water
algal blooms Depletion in soils
Mining, use (fertilizer, detergent, etc.)
increased runoff
Lithosphere
Hydrosphere
More Phos. for organisms
29
Sulfur Cycle
Bacteria Absorption
Atmosphere
Bacteria Release
Biosphere
Volcanoes Weathering
Absorption
Precipitation
Waste Decomposition
Weathering
Evaporation
Sedimentation
Lithosphere
Hydrosphere
Absorption
Deep Sea Vents
30
Sulfur Cycle
Human Impacts
Atmosphere
Biosphere
Net Effect Increase in atmosphere (health
effects) and acid rain
Precipitation Acid Rain
Burning Fossil Fuels
Lithosphere
Hydrosphere
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