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A model - data intercomparison of CO2 exchange across North America: Results from the North American Carbon Program site synthesis
Download2010
McCaughey, H., Sahoo, A. K., Riley, W., Lokupitiya, E., Price, D. T., Riciutto, D. M., Ciais, P., Dietze, M., Sprintsin, M., Liu, S. G., Chen, J. M., Barr, A., Law, B. E., Schwalm, C. R., Tian, H. Q., Oechel, W. C., Williams, C. A., Davis, K. J., Verma, S. B., Luo, Y. Q., Verbeeck, H., Tonitto, C., Dragoni, D., Peng, C. H., Margolis, H., Gu, L. H., Li, Z. P., Ma, S. Y., Matamala, R., Grant, R., Desai, A., Anderson, R., Hollinger, D., Flanagan, L. B., Fischer, M. L., Poulter, B., Li, L. H., Baker, I., Sun, J. E., Monson, R. K., Schaefer, K., Chen, G. S., Lafleur, P., Kucharik, C., Black, T.A., Izaurralde, R. C., Arain, M. A.
Abstract: Our current understanding of terrestrial carbon processes is represented in various models used to integrate and scale measurements of CO2 exchange from remote sensing and other spatiotemporal data. Yet assessments are rarely conducted to determine how well models simulate carbon...
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A model-data comparison of gross primary productivity: Results from the North American Carbon Program site synthesis
Download2012
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...
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2006
Wein, R.W., Cumming, S.G., Flannigan, M.D., Krawchuk, M.A.
Lighting, fire is the dominant natural disturbance of the western mixedwood boreal forest of North America. We quantified the independent effects of weather and forest composition oil lightning fire initiation (a detected and recorded fire start) patterns in Alberta, Canada, to demonstrate how...
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2004
Zwiers, F.W., Gillett, N.P., Flannigan, M.D., Weaver, A.J.
The area burned by forest fires in Canada has increased over the past four decades, at the same time as summer season temperatures have warmed. Here we use output from a coupled climate model to demonstrate that human emissions of greenhouse gases and sulfate aerosol have made a detectable...
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Ecological controls on net ecosystem productivity of a mesic arctic tundra under current and future climates
Download2011
Dimitrov, D. D., Grant, R. F., Lafleur, P. M., Humphreys, E. R.
Abstract: Changes in arctic C stocks with climate are thought to be caused by rising net primary productivity (NPP) during longer and warmer growing seasons, offset by rising heterotrophic respiration (Rh) in warmer and deeper soil active layers. In this study, we used the process model ecosys to...
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Fire regimes at the transition between mixedwood and coniferous boreal forest in northwestern Quebec.
Download2004
Flannigan, M., Kafka, V., Gauthier, S., Bergeron, Y.
Fire history was reconstructed for an area of 15 000 km2 located in the transition zone between the mixed and coniferous forests in Quebec's southern boreal forest. We used aerial photographs, archives, and dendroecological data (315 sites) to reconstruct a stand initiation map for the area. The...
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2002
Todd, J.B., Bosch, E.M., Logan, K.A., Mason, J.A., Skinner, W.R., Hirsch, K.G., Martell, D.L., Wotton, B.M., Flannigan, M.D., Stocks, B.J., Amiro, B.D.
A Large Fire Database (LFDB), which includes information on fire location, start date, final size, cause, and suppression action, has been developed for all fires larger than 200 ha in area for Canada for the 1959-1997 period. The LFDB represents only 3.1% of the total number of Canadian fires...
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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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Modeling the carbon balance of Amazonian rain forests: resolving ecological controls on net ecosystem productivity
Download2009
de Oliveira, R. C., Munger, J. W., Wofsy, S. C., Hutra, L. R., Grant, R. F., Saleska, S. R.
Abstract: There is still much uncertainty about ecological controls on the rate and direction of net CO(2) exchange by tropical rain forests, in spite of their importance to global C cycling. These controls are thought to arise from hydrologic and nutrient constraints to CO(2) fixation caused by...
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Modeling the effects of hydrology on gross primary productivity and net ecosystem productivity at Mer Bleue bog
Download2011
Humphreys, E., Dimitrov, D. D., Grant, R. F., LaFleur, P. M.
Abstract: The ecosys model was applied to investigate the effects of water table and subsurface hydrology changes on carbon dioxide exchange at the ombrotrophic Mer Bleue peatland, Ontario, Canada. It was hypothesized that (1) water table drawdown would not affect vascular canopy water potential,...