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Carbon Cycles Xiaoming Zou Institute for Tropical Ecosystem Studies, University of Puerto Rico
Carbon cycles Carbon cycles Ocean  Structure and properties Carbon distribution Atmosphere Structure and properties Carbon distribution Land Structure and properties Carbon distribution Global carbon cycles ,[object Object]
Global environmental changes
Natural rhythms and disturbances
Climate
Geological events
Anthropogenic influence
Land use
Fossil fuel combustion
Fertilizers and pollutants,[object Object]
Ocean Structure and Properties Ocean circulation Surface water Well mixed Warm water Little change in temperature Movement caused by wind  Earth rotation drives surface current from east to west along the equator Mean residence time 1700 years
Ocean Structure and Properties Ocean circulation Deep water Stratified Cold water with an average temperature of 3 C Sharp decrease in temperature in the thermocline, stable temperature further deeper Movement caused by water density and salinity Mean residence time 34000 years
Carbon Distribution in Ocean
Structure and Properties of the Atmosphere Structure and physical properties Troposphere (0-10 km) Stratosphere (10-50 km) Temperature Pressure (log P = - 0.06 A) Density
Global circulation Occurs in troposphere Upward near equator and at 60 degrees of latitude Downward at 30 and 90 degrees of latitude Structure and Properties of the Atmosphere
Carbon Distribution in Atmosphere
Atmospheric CO2 was much higher 390 M yrs ago than now
Lignin was evolved first in ferns 390 M yrs ago With lignin, plants could grow much taller and root deeply
Lignin decomposers were evolved at least 50 M yrs later Most coal formed during this mismatch  between lignin producers and decomposers.
Before combustion of fossil fuel for more than 650 thousand years, atmospheric CO2 has fluctuated between180 and 300 parts per million.
Now things are changing again,mostly from the burning of fossil fuels.
Structure and Properties of Land
Carbon Distribution on Land Light Altitude Latitude Aspects Water Nutrients
Carbon Distribution on Land
Global Carbon Cycle Pools Atmosphere 750 x 10^15 g Ocean water 38,000 x 10^15 g Plant biomass 560 x 10^15 g Soil organic matter and soil biomass 1,500 x 10^15 g  Total active pool: 40,000 x 10^15 Organic sediments 1.56 x 10^22 g Inorganic sediments 6.5 x 10^22 g
Global Carbon Cycle Fluxes Terrestrial GPP 120 x 10^15 g/y Ocean GPP 92 x 10^15 g/y Terrestrial Rp 60 x 10^15 g/y Terrestrial Rd 60 x 10^15 g/y Deforestation 0.9 x 10^15 g/y Anthropogenic 6 x 10^15 g/y Ocean R 90 x 10^15 g/y River flow 0.8 x 10^15 g/y

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Carbon cycles lecture

  • 1. Carbon Cycles Xiaoming Zou Institute for Tropical Ecosystem Studies, University of Puerto Rico
  • 2.
  • 4. Natural rhythms and disturbances
  • 10.
  • 11.
  • 12. Ocean Structure and Properties Ocean circulation Surface water Well mixed Warm water Little change in temperature Movement caused by wind Earth rotation drives surface current from east to west along the equator Mean residence time 1700 years
  • 13. Ocean Structure and Properties Ocean circulation Deep water Stratified Cold water with an average temperature of 3 C Sharp decrease in temperature in the thermocline, stable temperature further deeper Movement caused by water density and salinity Mean residence time 34000 years
  • 15.
  • 16.
  • 17. Structure and Properties of the Atmosphere Structure and physical properties Troposphere (0-10 km) Stratosphere (10-50 km) Temperature Pressure (log P = - 0.06 A) Density
  • 18.
  • 19.
  • 20. Global circulation Occurs in troposphere Upward near equator and at 60 degrees of latitude Downward at 30 and 90 degrees of latitude Structure and Properties of the Atmosphere
  • 22. Atmospheric CO2 was much higher 390 M yrs ago than now
  • 23. Lignin was evolved first in ferns 390 M yrs ago With lignin, plants could grow much taller and root deeply
  • 24. Lignin decomposers were evolved at least 50 M yrs later Most coal formed during this mismatch between lignin producers and decomposers.
  • 25. Before combustion of fossil fuel for more than 650 thousand years, atmospheric CO2 has fluctuated between180 and 300 parts per million.
  • 26. Now things are changing again,mostly from the burning of fossil fuels.
  • 28.
  • 29.
  • 30. Carbon Distribution on Land Light Altitude Latitude Aspects Water Nutrients
  • 31.
  • 33.
  • 34. Global Carbon Cycle Pools Atmosphere 750 x 10^15 g Ocean water 38,000 x 10^15 g Plant biomass 560 x 10^15 g Soil organic matter and soil biomass 1,500 x 10^15 g Total active pool: 40,000 x 10^15 Organic sediments 1.56 x 10^22 g Inorganic sediments 6.5 x 10^22 g
  • 35. Global Carbon Cycle Fluxes Terrestrial GPP 120 x 10^15 g/y Ocean GPP 92 x 10^15 g/y Terrestrial Rp 60 x 10^15 g/y Terrestrial Rd 60 x 10^15 g/y Deforestation 0.9 x 10^15 g/y Anthropogenic 6 x 10^15 g/y Ocean R 90 x 10^15 g/y River flow 0.8 x 10^15 g/y
  • 36. Global Carbon Cycle Residence time Atmosphere: 750/152 = 4.9 years Plant biomass: 560/60 = 9.3 years Soil organic C: 1500/60 = 25 years Surface ocean: 1020/90 = 11.3 years Entire ocean: 3800/90 = 422
  • 37. Mechanisms for Carbon Stabilization and Destabilization Reduction in decomposition of organic carbon Litter quality with high lignin content Land management (reduced earthworms, reduced O2 levels, increased N input, etc) Reduction in deforestation and combustion of fossil fuel Increase in primary productivity Iron fertilization in ocean Chemical fertilizers in land N2 fixation Increase inorganic carbon pool Increase ocean water pH Reduced acid rain
  • 38.
  • 39. Greenhouse Effect 1951-1997 Carbon dioxide (70%), nitrous oxide, methane (23%), ozone, chlorofluorocarbons (CFCs), and water vapor A molecule of methane is 21 times more potent than a molecule of carbon dioxide as a heat-trapping gas Vegetation has migrated since postglacial warming, but has failed to keep pace with changing climate because the greenhouse effect waarms 50-100 times faster than postglacial warming
  • 40. “Double loop" model of SOM dynamics CO2 Non-lignin decomposers Geochemical processes Non-lignin decomposers Lignolytic Microbes Physical Protection Slow C Active C Passive C Labile C decomposing Microbes Chemical bonding Lignolytic Microbes Microbial C Geochemical processes LOC/N control
  • 42. Global Environmental ChangesHuman Activities 1980 1994