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Skip to Search Results- 4Net primary production
- 3Nitrous-oxide
- 3Phosphorus uptake
- 3Root-growth
- 3Simulation-model
- 2Atmospheric carbon-dioxide
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Mathematical modeling of nitrous oxide emissions from an agricultural field during spring thaw
Download1999
Confidence in regional estimates of N2O emissions used in national greenhouse gas inventories could be improved by using mathematical models of the biological and physical processes by which these emissions are known to be controlled. However these models must first be rigorously tested against...
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Diurnal and annual exchanges of mass and energy between an aspen-hazelnut forest and the atmosphere: testing the mathematical model ecosys with data from the BOREAS experiment
Download1999
Russell, C., den Hartog, G., Grant, R.F., Berry, J.A., Yang, P.C., Neumann, H.H., Blanken, P.D., Black, T.A., Gower, S.T.
There is much uncertainty about the net carbon (C) exchange of boreal forest ecosystems, although this exchange may be an important part of global C dynamics. To resolve this uncertainty, net C exchange has been measured at several sites in the boreal forest of Canada as part of the Boreal...
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Carbon and energy exchange by a black spruce – moss ecosystem under changing climate: testing the mathematical model ecosys with data from the BOREAS experiment
Download2001
Grant, R.F., Berry, J.A., Wofsy, S.C., Goulden, M.L.
There is some uncertainty whether net ecosystem productivity (NEP) of boreal black spruce forests is positive or negative under current climates and how NEP would change under hypothesized changes in future climates. The mathematical model ecosys was used to examine NEP of a boreal black spruce...
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Comparison of boreal ecosystem model sensitivity to variability in climate and forest site parameters
Download2001
McGuire, A.D., Chen, J.M., Liu, J., Frolking, S.E., Wang, S., Potter, C.S., Amthor, J.S., Nikolov, N.T., Clein, J.S., Kimball, J.S., King, A.W., Grant, R.F.
Ecosystem models are useful tools for evaluating environmental controls on carbon and water cycles under past or future conditions. In this paper we compare annual carbon and water fluxes from nine boreal spruce forest ecosystem models in a series of sensitivity simulations. For each comparison,...
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Boreal forest CO2 exchange and evapotranspiration predicted by nine ecosystem process models: Inter-model comparisons and relationships to field measurements
Download2001
Wofsy, S.C., Frolking, S.E., Wang, S., Clein, J.S., McGuire, A.D., Potter, C.S., Goulden, M.L., Chen, J.M., Grant, R.F., Nikolov, N.T., Amthor, J.S., Kimball, J.S., King, A.W.
Nine ecosystem process models were used to predict CO2 and water vapor exchanges by a 150-year-old black spruce forest in central Canada during 1994-1996 to evaluate and improve the models. Three models had hourly time steps, five had daily time steps, and one had monthly time steps. Model input...
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Controls on carbon and energy exchange by a black spruce–moss ecosystem: Testing the mathematical model Ecosys with data from the BOREAS Experiment
Download2001
Massheder, J.M., Berry, J.A., Scott, S.L., Rayment, M., Jarvis, P.G., Grant, R.F., Hale, S.E., Moncrieff, J.B.
Stomatal limitations to mass and energy exchange over boreal black spruce forests may be caused by low needle N concentrations that limit CO(2) fixation rates. These low concentrations may be caused by low N uptake rates from cold boreal soils with high soil C:N ratios and by low N deposition...
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Methane efflux form boreal wetlands: theory and testing of the ecosystem model ecosys with chamber and tower flux measurements
Download2002
A robust model of CH4 emission from terrestrial ecosystems should be capable of simulating the temporal and spatial variability that characterizes field measurements. Such a model should couple a biologically based treatment of microbial CH4 transformations with a physically based treatment of...
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Oak forest carbon and water simulations: model intercomparisons and evaluations against independent data
Download2004
Baldocchi, D.D., Luo, Y., Grant, R.F., Hui, D., Amthor, J.S., Sun, G., Wullschleger, S.D., King, A.W., Johnson, D.W., Hanson, P.J., Williams, M., Thornton, P.E., Hartley, A., Kimball, J.S., Cushman, R.M., Hunt Jr., E.R., McNulty, S.G., Wang, S., Wilson, K.B.
Models represent our primary method for integration of small-scale, process-level phenomena into a comprehensive description of forest-stand or ecosystem function. They also represent a key method for testing hypotheses about the response of forest ecosystems to multiple changing environmental...
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Modeling stomatal and nonstomatal effects of water deficits on CO2 fixation in a semiarid grassland
Download2007
The confidence with which we can model water deficit effects on grassland productivity is limited by uncertainty about the mechanisms, stomatal and nonstomatal, by which soil water deficits reduce CO2 uptake. We propose that these reductions can accurately be modeled from a combination of...
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Temperature sensitivity of N2O emissions from fertilized agricultural soils: Mathematical modeling in ecosys
Download2008
N2O emissions have been found to be highly sensitive to soil temperature (T-s) which may cause substantial rises in emissions with rises in Ts expected in most climate change scenarios. Mathematical models used to project changes in emissions during climate change should be able to simulate the...