A model‐data intercomparison of CO2 exchange across North America: Results from the North American Carbon Program site synthesis

[1] 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 processes across vegetation types and environmental conditions. Using standardized data from the North American Carbon Program we compare observed and simulated monthly CO2 exchange from 44 eddy covariance flux towers in North America and 22 terrestrial biosphere models. The analysis period spans ∼220 site-years, 10 biomes, and includes two large-scale drought events, providing a natural experiment to evaluate model skill as a function of drought and seasonality. We evaluate models' ability to simulate the seasonal cycle of CO2 exchange using multiple model skill metrics and analyze links between model characteristics, site history, and model skill. Overall model performance was poor; the difference between observations and simulations was ∼10 times observational uncertainty, with forested ecosystems better predicted than nonforested. Model-data agreement was highest in summer and in temperate evergreen forests. In contrast, model performance declined in spring and fall, especially in ecosystems with large deciduous components, and in dry periods during the growing season. Models used across multiple biomes and sites, the mean model ensemble, and a model using assimilated parameter values showed high consistency with observations. Models with the highest skill across all biomes all used prescribed canopy phenology, calculated NEE as the difference between GPP and ecosystem respiration, and did not use a daily time step.

[1]  Wei-Yin Loh,et al.  Classification and regression trees , 2011, WIREs Data Mining Knowl. Discov..

[2]  W. Landman.  Climate change 2007: the physical science basis , 2010 .

[3]  Ge Sun,et al.  Model estimates of net primary productivity, evapotranspiration, and water use efficiency in the terrestrial ecosystems of the southern United States during 1895–2007 , 2010 .

[4]  A. Arneth,et al.  Assimilation exceeds respiration sensitivity to drought: A FLUXNET synthesis , 2010 .

[5]  Huajun Tang,et al.  Modelling impacts of alternative farming management practices on greenhouse gas emissions from a winter wheat-maize rotation system in China , 2010 .

[6]  Markus Reichstein,et al.  CO2 Flux Measurement Uncertainty Estimates for NACP , 2010 .

[7]  K. Davis,et al.  How uncertainty in gap-filled meteorological input forcing at eddy covariance sites impacts modeled carbon and energy flux (Invited) , 2009 .

[8]  Christoph Thomas,et al.  Seasonal hydrology explains interannual and seasonal variation in carbon and water exchange in a semiarid mature ponderosa pine forest in central Oregon , 2009 .

[9]  Markus Reichstein,et al.  Biosphere-atmosphere exchange of CO2 in relation to climate: a cross-biome analysis across multiple time scales , 2009 .

[10]  Jennifer Nakamura,et al.  Drought in the Southeastern United States: Causes, Variability over the Last Millennium, and the Potential for Future Hydroclimate Change* , 2009 .

[11]  A. Ito,et al.  Multi-model analysis of terrestrial carbon cycles in Japan: reducing uncertainties in model outputs among different terrestrial biosphere models using flux observations , 2009 .

[12]  C. Williams,et al.  Complexity in water and carbon dioxide fluxes following rain pulses in an African savanna , 2009, Oecologia.

[13]  Gregory J. Carbone,et al.  Ensemble Forecasts of Drought Indices Using a Conditional Residual Resampling Technique , 2009 .

[14]  Ankur R. Desai,et al.  Contrasting carbon dioxide fluxes between a drying shrub wetland in Northern Wisconsin, USA, and nearby forests , 2009 .

[15]  E. Lokupitiya,et al.  Incorporation of crop phenology in Simple Biosphere Model (SiBcrop) to improve land-atmosphere carbon exchanges from croplands , 2009 .

[16]  T. Black,et al.  Carbon sequestration in boreal jack pine stands following harvesting , 2009 .

[17]  A. Slater,et al.  Improving simulated soil temperatures and soil freeze/thaw at high‐latitude regions in the Simple Biosphere/Carnegie‐Ames‐Stanford Approach model , 2009 .

[18]  Eero Nikinmaa,et al.  Exceptional carbon uptake in European forests during the warm spring of 2007: a data–model analysis , 2009 .

[19]  S. Wofsy,et al.  Mechanistic scaling of ecosystem function and dynamics in space and time: Ecosystem Demography model version 2 , 2009 .

[20]  D. Hollinger,et al.  Influence of spring phenology on seasonal and annual carbon balance in two contrasting New England forests. , 2009, Tree physiology.

[21]  B. Law,et al.  Random and systematic CO2 flux sampling errors for tower measurements over forests in the convective boundary layer , 2009 .

[22]  C. Peng,et al.  Simulating carbon exchange in Canadian Boreal forests: I. Model structure, validation, and sensitivity analysis , 2008 .

[23]  Richard A. Birdsey,et al.  Tree age, disturbance history, and carbon stocks and fluxes in subalpine Rocky Mountain forests , 2008 .

[24]  D. E. Schorran,et al.  Prolonged suppression of ecosystem carbon dioxide uptake after an anomalously warm year , 2008, Nature.

[25]  I. C. Prentice,et al.  Evaluation of the terrestrial carbon cycle, future plant geography and climate‐carbon cycle feedbacks using five Dynamic Global Vegetation Models (DGVMs) , 2008 .

[26]  A. Scott Denning,et al.  Combined Simple Biosphere/Carnegie‐Ames‐Stanford Approach terrestrial carbon cycle model , 2008 .

[27]  Yiqi Luo,et al.  Soil hydrological properties regulate grassland ecosystem responses to multifactor global change: A modeling analysis , 2008 .

[28]  S. Pacala,et al.  Predictive Models of Forest Dynamics , 2008, Science.

[29]  Nuno Carvalhais,et al.  Implications of the carbon cycle steady state assumption for biogeochemical modeling performance and inverse parameter retrieval , 2008 .

[30]  E. Wood,et al.  Projected changes in drought occurrence under future global warming from multi-model, multi-scenario, IPCC AR4 simulations , 2008 .

[31]  Akihiko Ito,et al.  The regional carbon budget of East Asia simulated with a terrestrial ecosystem model and validated using AsiaFlux data , 2008 .

[32]  S. Frolking,et al.  McGill wetland model: evaluation of a peatland carbon simulator developed for global assessments , 2008 .

[33]  Scott D. Miller,et al.  Seasonal drought stress in the Amazon: Reconciling models and observations , 2008 .

[34]  D. Baldocchi.  ‘Breathing’ of the terrestrial biosphere: lessons learned from a global network of carbon dioxide flux measurement systems , 2008 .

[35]  P. Ciais,et al.  Net carbon dioxide losses of northern ecosystems in response to autumn warming , 2008, Nature.

[36]  Matthias Peichl,et al.  Allometry and partitioning of above- and belowground tree biomass in an age-sequence of white pine forests , 2007 .

[37]  D. Baldocchi,et al.  Inter-annual variability in carbon dioxide exchange of an oak/grass savanna and open grassland in California , 2007 .

[38]  D. Hollinger,et al.  A method to estimate the additional uncertainty in gap-filled NEE resulting from long gaps in the CO2 flux record , 2007 .

[39]  Markus Reichstein,et al.  Uncertainties of modeling gross primary productivity over Europe: A systematic study on the effects of using different drivers and terrestrial biosphere models , 2007 .

[40]  M. Heimann,et al.  Comprehensive comparison of gap-filling techniques for eddy covariance net carbon fluxes , 2007 .

[41]  R. Seager.  The Turn of the Century North American Drought: Global Context, Dynamics, and Past Analogs* , 2007 .

[42]  R. Stöckli,et al.  Temperature anomaly reemergence in seasonally frozen soils , 2007 .

[43]  T. McMahon,et al.  Updated world map of the Köppen-Geiger climate classification , 2007 .

[44]  C. Kucharik,et al.  Residue, respiration, and residuals: Evaluation of a dynamic agroecosystem model using eddy flux measurements and biometric data , 2007 .

[45]  Markus Reichstein,et al.  Assessing the ability of three land ecosystem models to simulate gross carbon uptake of forests from boreal to Mediterranean climate in Europe , 2007 .

[46]  Randy L. Raper,et al.  Simulating Field-Scale Soil Organic Carbon Dynamics Using EPIC , 2007 .

[47]  David P. Billesbach,et al.  Spatiotemporal Variations in Growing Season Exchanges of CO2, H2O, and Sensible Heat in Agricultural Fields of the Southern Great Plains , 2007 .

[48]  S. Wofsy,et al.  Factors controlling CO2 exchange on timescales from hourly to decadal at Harvard Forest , 2007 .

[49]  R. Seager,et al.  Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America , 2007, Science.

[50]  Steven F. Oberbauer,et al.  TUNDRA CO2 FLUXES IN RESPONSE TO EXPERIMENTAL WARMING ACROSS LATITUDINAL AND MOISTURE GRADIENTS , 2007 .

[51]  Paul W. Stackhouse,et al.  Climate-induced boreal forest change: Predictions versus current observations , 2007 .

[52]  Markus Reichstein,et al.  Evidence for soil water control on carbon and water dynamics in European forests during the extremely dry year: 2003 , 2007 .

[53]  Natascha Kljun,et al.  Climatic controls on the carbon and water balances of a boreal aspen forest, 1994–2003 , 2007 .

[54]  Edward R. Cook,et al.  North American drought: Reconstructions, causes, and consequences , 2007 .

[55]  T. Andrew Black,et al.  A method for deriving net primary productivity and component respiratory fluxes from tower‐based eddy covariance data: a case study using a 17‐year data record from a Douglas‐fir chronosequence , 2007 .

[56]  W. Oechel,et al.  Mature semiarid chaparral ecosystems can be a significant sink for atmospheric carbon dioxide , 2007 .

[57]  T. A. Black,et al.  Comparison of carbon dioxide fluxes over three boreal black spruce forests in Canada , 2007 .

[58]  K. Trenberth,et al.  Observations: Surface and Atmospheric Climate Change , 2007 .

[59]  T. A. Black,et al.  Photosynthetic light use efficiency of three biomes across an east–west continental-scale transect in Canada , 2006 .

[60]  Lawrence B. Flanagan,et al.  Environmental control of net ecosystem CO2 exchange in a treed, moderately rich fen in northern Alberta , 2006 .

[61]  T. A. Black,et al.  Soil-plant nitrogen cycling modulated carbon exchanges in a western temperate conifer forest in Canada , 2006 .

[62]  M. A. Arain,et al.  Carbon dioxide and energy fluxes from a boreal mixedwood forest ecosystem in Ontario, Canada , 2006 .

[63]  Oliver Sonnentag,et al.  Leaf area index measurements at Fluxnet-Canada forest sites , 2006 .

[64]  T. Vesala,et al.  Towards a standardized processing of Net Ecosystem Exchange measured with eddy covariance technique: algorithms and uncertainty estimation , 2006 .

[65]  A. Mishra,et al.  Drought forecasting using feed-forward recursive neural network , 2006 .

[66]  Mark Heuer,et al.  Direct and indirect effects of atmospheric conditions and soil moisture on surface energy partitioning revealed by a prolonged drought at a temperate forest site , 2006 .

[67]  Jehn-Yih Juang,et al.  Multiscale model intercomparisons of CO2 and H2O exchange rates in a maturing southeastern US pine forest , 2006 .

[68]  T. Huntington.  Evidence for intensification of the global water cycle: Review and synthesis , 2006 .

[69]  R. Schnur,et al.  Climate-carbon cycle feedback analysis: Results from the C , 2006 .

[70]  Pierre Friedlingstein,et al.  Comparing and evaluating process‐based ecosystem model predictions of carbon and water fluxes in major European forest biomes , 2005, Global change biology.

[71]  Jing M. Chen,et al.  Intercomparison of techniques to model high temperature effects on CO2 and energy exchange in temperate and boreal coniferous forests , 2005 .

[72]  P. Ciais,et al.  Europe-wide reduction in primary productivity caused by the heat and drought in 2003 , 2005, Nature.

[73]  S. Running,et al.  Biome-BGC: Terrestrial Ecosystem Process Model, Version 4.1.1 , 2005 .

[74]  C J Tucker,et al.  Drier summers cancel out the CO2 uptake enhancement induced by warmer springs. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[75]  Andrew E. Suyker,et al.  Annual carbon dioxide exchange in irrigated and rainfed maize-based agroecosystems , 2005 .

[76]  Robert Clement,et al.  On the validation of models of forest CO2 exchange using eddy covariance data: some perils and pitfalls. , 2005, Tree physiology.

[77]  Jehn-Yih Juang,et al.  Variability in net ecosystem exchange from hourly to inter-annual time scales at adjacent pine and hardwood forests: a wavelet analysis. , 2005, Tree physiology.

[78]  I. C. Prentice,et al.  A dynamic global vegetation model for studies of the coupled atmosphere‐biosphere system , 2005 .

[79]  K. Davis,et al.  Comparing net ecosystem exchange of carbon dioxide between an old-growth and mature forest in the upper Midwest, USA , 2005 .

[80]  K. Trenberth,et al.  A Global Dataset of Palmer Drought Severity Index for 1870–2002: Relationship with Soil Moisture and Effects of Surface Warming , 2004 .

[81]  T. Black,et al.  Inter-annual variability in the leaf area index of a boreal aspen-hazelnut forest in relation to net ecosystem production , 2004 .

[82]  K. Davis,et al.  Carbon exchange and venting anomalies in an upland deciduous forest in northern Wisconsin, USA , 2004 .

[83]  E. Cook,et al.  Long-Term Aridity Changes in the Western United States , 2004, Science.

[84]  B. McCarl,et al.  Enhancement of Carbon Sequestration in US Soils , 2004 .

[85]  G. Meehl,et al.  More Intense, More Frequent, and Longer Lasting Heat Waves in the 21st Century , 2004, Science.

[86]  B. Law,et al.  Age-related changes in ecosystem structure and function and effects on water and carbon exchange in ponderosa pine. , 2004, Tree physiology.

[87]  K. Wilson,et al.  OAK FOREST CARBON AND WATER SIMULATIONS: MODEL INTERCOMPARISONS AND EVALUATIONS AGAINST INDEPENDENT DATA , 2004 .

[88]  William W. Hargrove,et al.  New analysis reveals representativeness of the AmeriFlux network , 2003 .

[89]  Kenneth J. Davis,et al.  The annual cycles of CO2 and H2O exchange over a northern mixed forest as observed from a very tall tower , 2003 .

[90]  Hans Peter Schmid,et al.  Ecosystem‐atmosphere exchange of carbon dioxide over a mixed hardwood forest in northern lower Michigan , 2003 .

[91]  T. A. Black,et al.  Ecophysiological controls on the carbon balances of three southern boreal forests , 2003 .

[92]  Shuguang Liu,et al.  Modeling carbon dynamics in vegetation and soil under the impact of soil erosion and deposition , 2003 .

[93]  Steve Frolking,et al.  Interannual variability in the peatland‐atmosphere carbon dioxide exchange at an ombrotrophic bog , 2003 .

[94]  S. Verma,et al.  Interannual variability in net CO2 exchange of a native tallgrass prairie , 2003 .

[95]  Rommel C. Zulueta,et al.  Inter-annual carbon dioxide uptake of a wet sedge tundra ecosystem in the Arctic , 2003 .

[96]  T. Griffisa,et al.  Ecophysiological controls on the carbon balances of three southern boreal forests , 2003 .

[97]  R. O N A L,et al.  The annual cycles of CO 2 and H 2 O exchange over a northern mixed forest as observed from a very tall tower , 2003 .

[98]  Xiwu Zhan,et al.  An analytical approach for estimating CO2 and heat fluxes over the Amazonian region , 2003 .

[99]  J. Berry,et al.  A mechanistic model of H218O and C18OO fluxes between ecosystems and the atmosphere: Model description and sensitivity analyses , 2002 .

[100]  M. Noguer,et al.  Climate change 2001: The scientific basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change , 2002 .

[101]  Lawrence B. Flanagan,et al.  Seasonal and interannual variation in carbon dioxide exchange and carbon balance in a northern temperate grassland , 2002 .

[102]  J. Berry,et al.  A Mechanistic Model of H 218 O and C 18 OO Fluxes between Ecosystems and the Atmosphere: Model Description and Sensitivity Analyses , 2002 .

[103]  J. Houghton,et al.  Climate change 2001 : the scientific basis , 2001 .

[104]  John S. Kimball,et al.  Boreal forest CO2 exchange and evapotranspiration predicted by nine ecosystem process models: Intermodel comparisons and relationships to field measurements , 2001 .

[105]  James A. Bradford,et al.  Carbon dioxide fluxes in a southern plains prairie , 2001 .

[106]  W. Oechel,et al.  FLUXNET: A New Tool to Study the Temporal and Spatial Variability of Ecosystem-Scale Carbon Dioxide, Water Vapor, and Energy Flux Densities , 2001 .

[107]  K. Taylor.  Summarizing multiple aspects of model performance in a single diagram , 2001 .

[108]  Hans Peter Schmid,et al.  Measurements of CO2 and energy fluxes over a mixed hardwood forest in the mid-western United States , 2000 .

[109]  Limin Yang,et al.  Development of a global land cover characteristics database and IGBP DISCover from 1 km AVHRR data , 2000 .

[110]  C. Somerville.  Department of plant biology , 2000 .

[111]  Hans Peter Schmid,et al.  Measurements of CO 2 and energy fluxes over a mixed hardwood forest in the mid-western United States , 2000 .

[112]  J. Chen,et al.  Net primary productivity distribution in the BOREAS region from a process model using satellite and surface data , 1999 .

[113]  Peter E. Thornton,et al.  Generating surfaces of daily meteorological variables over large regions of complex terrain , 1997 .

[114]  C. D. Keeling,et al.  Increased activity of northern vegetation inferred from atmospheric CO2 measurements , 1996, Nature.

[115]  T. McKee,et al.  THE RELATIONSHIP OF DROUGHT FREQUENCY AND DURATION TO TIME SCALES , 1993 .

[116]  A. Tamhane,et al.  Multiple Comparison Procedures. , 1989 .

[117]  J. Taylor.  An Introduction to Error Analysis , 1982 .

[118]  W. Larcher.  Physiological Plant Ecology , 1977 .

[119]  W M Davis,et al.  A GRADUATE SCHOOL OF GEOGRAPHY. , 2010, Science.

[120]  S S I T C H,et al.  Evaluation of Ecosystem Dynamics, Plant Geography and Terrestrial Carbon Cycling in the Lpj Dynamic Global Vegetation Model , 2022 .