ForestDNDC Processbased biogeochemical model

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Forest-DNDCProcess-based biogeochemical model

• Forest-DNDC is a member of DNDC family, used to
  simulate the interaction between soil and plant
  based on the balances of materials and energy in
  forest ecosystems.

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Forest-DNDC
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Soil C Pools and Fluxes in Forest-DNDC
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Microbial activity is driven by two nutrients

• P Pmax C/(KcC) O/(KoO)
• P - reaction rate
• Pmax - maximum reaction rate
• C, O - concentrations of substrates C and O
• Kc, Ko - half-saturation constants for substrate
  C and O

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Plant submodel
Water demand
Leaf stem respiration
Photosynthesis
Energy
Water uptake by roots
Biomass production
CO2
Leaf N
N demand
Water stress
Grain
Soil
Transpiration
N uptake by roots
Stalks
Roots
Root respiration
Decomposition
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Eh is determined by concentrations of the
dominant oxidizing vs. reducing species in a
redox reaction system.

• Eh Eo rT/nF ln(O/R)
• Eh - redox potential, volts
• Eo - standard redox potential, volts
• r - gas constant
• T - temperature, in kelvins
• n - number of exchanged electrons
• F - Faraday constant
• O - concentration of oxidant, mol
• R - concentration of reductant, mol

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Measured and Modeled CH4 Fluxes from Wetlands in
North America(Field data from Suyker et al.,
1997, Crill et al. 1988, and Dise 1991)
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Soil Respiration
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Topsoil Temperature (0-10cm)
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N2O CH4 released from soil
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Photosynthesis CO2
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Simulated by DNDC for plot 24
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Thank you !