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2012

Anderson, R., Poulter, B., Matamala, R., Lokipitiya, E., Chen, J.M., Verbeeck, H., Davis, K.J., Weng, E., Curtis, P.S., Tonitto, C., Munger, J.W., Ricciuto, D., Chen, J., Gu, L., Humphreys, E., Desai, A.R., Price, D.T., Raczka, B.M., Zhou, X., Peng, C., Torn, M., Hollinger, D.Y., Riley, W.J., Roulet, N., Black, A., Bolstad, P., Baker, I., Thornton, P., Monson, R., Jain, A., Law, B., Gough, C., Margolis, H.A., Dimitrov, D., Grant, R.F., Liu, S., McCaughey, J.H., Hilton, T.W., Sahoo, A., Dietze, M., Schaefer, K., Williams, C., Dragoni, D., Tian, H., Vargas, R., Schwalm, C.R., Richardson, A.D., Oechel, W., Kucharik, C., Barr, A., Altaf Arain, M.

Accurately simulating gross primary productivity (GPP) in terrestrial ecosystem models is critical because errors in simulated GPP propagate through the model to introduce additional errors in simulated biomass and other fluxes. We evaluated simulated, daily average GPP from 26 models against...

2001

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...

2001

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...

2011

Black, T.A., Izaurralde, R.C., Lokupitiya, E., Munger, J.W., Schaefer, K., Weng, E., Richardson, A.D., Altaf Arain, M., Luo, Y., Ciais, P., Ricciuto, D.M., Stoy, P.C., Dietze, M.C., Poulter, B., Barr, A.G., Liu, S., Hollinger, D., Tian, H., Suyker, A.E., Verbeeck, H., Price, D.T., Grant, R.F., Peng, C., Baker, I.T., Vargas, R., Anderson, R.S., Tonitto, C., Sahoo, A.K., Chen, J.M., Flanagan, L.B., Riley, W.J., Wang, W., Lafleur, P., Gough, C.M., Verma, S.B., Kucharik, C.J.

Ecosystem models are important tools for diagnosing the carbon cycle and projecting its behavior across space and time. Despite the fact that ecosystems respond to drivers at multiple time scales, most assessments of model performance do not discriminate different time scales. Spectral methods,...

2001

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,...

2001

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...

1999

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...

1999

Grant, R.F., Pattey, E.

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...

2002

Roulet, N.T., Grant, R.F.

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...

2007

Flanagan, L.B., Grant, R.F.

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...