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Title: Global parameterization and validation of a two‐leaf light use efficiency model for predicting gross primary production across FLUXNET sites

Journal Article · · Journal of Geophysical Research. Biogeosciences
DOI:https://doi.org/10.1002/2014JG002876· OSTI ID:1246570
 [1];  [2];  [3];  [2];  [4];  [4];  [5];  [6];  [6];  [7];  [8];  [9];  [10];  [11];  [12];  [4];  [13];  [14];  [15];  [16] more »;  [17];  [18];  [19];  [20];  [21];  [22];  [23];  [24];  [25];  [26];  [27];  [28];  [29];  [30] « less
  1. Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, School of Geographic and Oceanographic SciencesNanjing University Nanjing China, Joint Center for Global Change Studies Beijing China
  2. Joint Center for Global Change Studies Beijing China, International Institute for Earth System SciencesNanjing University Nanjing China
  3. International Institute for Earth System SciencesNanjing University Nanjing China, Jiangsu Center for Collaborative Innovation in Geographic Information Resource Development and Application Nanjing China
  4. Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources Research, Chinese Academy of Science Beijing China
  5. State Key Laboratory of Earth Surface Processes and Resource EcologyFuture Earth Research Institute, Beijing Normal University Beijing China
  6. Faculty of Land and Food SystemsUniversity of British Columbia Vancouver British Columbia Canada
  7. Department of Environmental EngineeringTechnical University of Denmark (DTU) Kgs. Lyngby Denmark
  8. Institute of Applied EcologyChinese Academy of Sciences Shenyang China
  9. South China Botanical GardenChinese Academy of Sciences Guangzhou China
  10. Centre for Forest StudiesFaculty of Forestry, Geography and Geomatics, Laval University Quebec City Quebec Canada
  11. CIRAD‐PersystUMR Ecologie Fonctionnelle and Biogéochimie des Sols et Agroécosystèmes, SupAgro‐CIRAD‐INRA‐IRD Montpellier France, CATIE (Tropical Agricultural Centre for Research and Higher Education) Turrialba Costa Rica
  12. Northwest Institute of Plateau BiologyChinese Academy of Sciences Xining China
  13. Environmental Research Institute, Civil and Environmental Engineering DepartmentUniversity College Cork Cork Ireland
  14. Department of Biological SciencesUniversity of Alabama Tuscaloosa Alabama USA
  15. Laboratory of Plants Ecological PhysiologyInstitute of Systems Biology and Ecology AS CR Prague Czech Republic
  16. Forest ServicesAutonomous Province of Bolzano Bolzano Italy, Faculty of Sciences and TechnologyFree University of Bolzano Bolzano Italy
  17. Institute for EcologyUniversity of Innsbruck Innsbruck Austria, European Academy of Bolzano Bolzano Italy
  18. Grassland Sciences GroupInstitute of Agricultural Sciences ETH Zurich Switzerland
  19. Atmospheric and Climate Research Program, Environmental Science DivisionArgonne National Laboratory Argonne Illinois USA
  20. McMaster Centre for Climate Change and School of Geography and Earth SciencesMcMaster University Hamilton Ontario Canada
  21. INRA NancyUMR EEF Champenoux France
  22. School of Earth and EnvironmentThe University of Western Australia Crawley Australia
  23. Department of GeographyUniversity of Colorado Boulder Boulder Colorado USA
  24. UMR ECOSYSINRA, AgroParisTech, Université Paris‐Saclay Thiverval‐Grignon France
  25. Department of Crop and Soil Sciences, College of Agricultural and Environmental SciencesUniversity of Georgia Athens Georgia USA
  26. Viea San Camillo Ed LellisViterboUniversity of Tuscia Viterbo Italy
  27. MTA‐SZIE Plant Ecology Research GroupSzent Istvan University Godollo Hungary
  28. Meteorology DepartmentPoznan University of Life Sciences Poznan Poland, Department of Matter and Energy FluxesGlobal Change Research Center Brno Czech Republic
  29. Department of Land, Air and Water ResourcesUniversity of California Davis California USA, Joint Program on the Science and Policy of Global ChangeMassachusetts Institute of Technology Cambridge USA
  30. A.N. Severtsov Institute of Ecology and EvolutionRussian Academy of Sciences Moscow Russia
+ Show Author Affiliations

Light use efficiency (LUE) models are widely used to simulate gross primary production (GPP). However, the treatment of the plant canopy as a big leaf by these models can introduce large uncertainties in simulated GPP. Recently, a two-leaf light use efficiency (TL-LUE) model was developed to simulate GPP separately for sunlit and shaded leaves and has been shown to outperform the big-leaf MOD17 model at 6 FLUX sites in China. In this study we investigated the performance of the TL-LUE model for a wider range of biomes. For this we optimized the parameters and tested the TL-LUE model using data from 98 FLUXNET sites which are distributed across the globe. The results showed that the TL-LUE model performed in general better than the MOD17 model in simulating 8-day GPP. Optimized maximum light use efficiency of shaded leaves (εmsh) was 2.63 to 4.59 times that of sunlit leaves (εmsu). Generally, the relationships of εmsh and εmsu with εmax were well described by linear equations, indicating the existence of general patterns across biomes. GPP simulated by the TL-LUE model was much less sensitive to biases in the photosynthetically active radiation (PAR) input than the MOD17 model. The results of this study suggest that the proposed TL-LUE model has the potential for simulating regional and global GPP of terrestrial ecosystems and it is more robust with regard to usual biases in input data than existing approaches which neglect the bi-modal within-canopy distribution of PAR.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER); National Natural Science Foundation of China (NSFC); Chinese Academy of Sciences (CAS); National Science Foundation (NSF)
Grant/Contract Number:
AC02-06CH11357; 41371070; CCSF201412; XDA05050602-1; EF1137306/MIT; DBI-0620409; DEB-9910514; FG02-04ER63917; FG02-04ER63911
OSTI ID:
1246570
Alternate ID(s):
OSTI ID: 1246571; OSTI ID: 1287442
Journal Information:
Journal of Geophysical Research. Biogeosciences, Journal Name: Journal of Geophysical Research. Biogeosciences Vol. 121 Journal Issue: 4; ISSN 2169-8953
Publisher:
American Geophysical UnionCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 87 works
Citation information provided by
Web of Science

References (160)

Development of a two-leaf light use efficiency model for improving the calculation of terrestrial gross primary productivity journal May 2013
Global and direct photosynthetically active radiation parameterizations for clear-sky conditions journal January 2009
Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems: past, present and future journal April 2003
Identification of a general light use efficiency model for gross primary production journal January 2011
A new segmentation method of electroencephalograms by use of Akaike's information criterion journal December 1995
Long term and seasonal courses of leaf area index in a semi-arid forest plantation journal May 2011
Footprint modeling for vegetation atmosphere exchange studies: a review and perspective journal December 2002
Parameterization of a diagnostic carbon cycle model for continental scale application journal July 2011
Increased carbon sequestration by a boreal deciduous forest in years with a warm spring journal May 2000
Direct observations of the effects of aerosol loading on net ecosystem CO 2 exchanges over different landscapes journal January 2004
Factors controlling the interannual variability in the carbon balance of a southern boreal black spruce forest journal January 2008
Evaluation of remote sensing based terrestrial productivity from MODIS using regional tower eddy flux network observations journal July 2006
On the direct effect of clouds and atmospheric particles on the productivity and structure of vegetation journal September 2001
Global dimming: a review of the evidence for a widespread and significant reduction in global radiation with discussion of its probable causes and possible agricultural consequences journal April 2001
Long term carbon dioxide exchange above a mixed forest in the Belgian Ardennes journal July 2001
Variation in photosynthetic light-use efficiency in a mountainous tropical rain forest in Indonesia journal April 2008
Partitioning solar radiation into direct and diffuse, visible and near-infrared components journal April 1985
Effects of cloudiness change on net ecosystem exchange, light use efficiency, and water use efficiency in typical ecosystems of China journal July 2011
Terrestrial Gross Carbon Dioxide Uptake: Global Distribution and Covariation with Climate journal July 2010
First operational BRDF, albedo nadir reflectance products from MODIS journal November 2002
Comparing net ecosystem exchange of carbon dioxide between an old-growth and mature forest in the upper Midwest, USA journal January 2005
Improvements of the MODIS terrestrial gross and net primary production global data set journal March 2005
Effects of canopy photosynthesis saturation on the estimation of gross primary productivity from MODIS data in a tropical forest journal June 2012
The carbon uptake of a mid latitude pine forest growing on sandy soil journal May 2002
A data-driven analysis of energy balance closure across FLUXNET research sites: The role of landscape scale heterogeneity journal April 2013
Carbon sequestration in a high-elevation, subalpine forest journal May 2002
Constraints to growth of boreal forests journal June 2000
Evaluation of MODIS gross primary productivity for Africa using eddy covariance data journal April 2013
Using watershed water balance to evaluate the accuracy of eddy covariance evaporation measurements for three semiarid ecosystems journal February 2010
Treatment and assessment of the CO2-exchange at a complex forest site in Thuringia, Germany journal May 2010
Evaluating terrestrial CO 2 flux diagnoses and uncertainties from a simple land surface model and its residuals journal January 2014
A two-leaf model for canopy conductance, photosynthesis and partitioning of available energy I: journal May 1998
Impact of changes in diffuse radiation on the global land carbon sink journal April 2009
Theoretical uncertainty analysis of global MODIS, CYCLOPES, and GLOBCARBON LAI products using a triple collocation method journal September 2012
Globalland30 Mapping Capacity of Land Surface Water in Thessaly, Greece journal December 2014
A new assessment of European forests carbon exchanges by eddy fluxes and artificial neural network spatialization journal April 2003
Measurements of CO2 and energy fluxes over a mixed hardwood forest in the mid-western United States journal July 2000
Net ecosystem production in a temperate pine plantation in southeastern Canada journal February 2005
Effects of climate variability on the carbon dioxide, water, and sensible heat fluxes above a ponderosa pine plantation in the Sierra Nevada (CA) journal March 2000
An algorithm for the retrieval of albedo from space using semiempirical BRDF models journal March 2000
Species differences in stomatal control of water loss at the canopy scale in a mature bottomland deciduous forest journal December 2003
Seasonal variation in carbon dioxide exchange over a Mediterranean annual grassland in California journal May 2004
A decade of carbon, water and energy flux measurements of an old spruce forest at the Anchor Station Tharandt journal January 2007
On the Temperature Dependence of Soil Respiration journal June 1994
Locally adjusted cubic-spline capping for reconstructing seasonal trajectories of a satellite-derived surface parameter journal August 2006
Carbon dioxide fluxes in coastal Douglas-fir stands at different stages of development after clearcut harvesting journal November 2006
The ratio of transmitted near-infrared radiation to photosynthetically active radiation (PAR) increases in proportion to the adsorbed PAR in the canopy journal April 2010
Environmental controls over net ecosystem carbon exchange of scrub oak in central Florida journal December 2006
Carbon balance of a southern taiga spruce stand in European Russia journal November 2002
A new look at the statistical model identification journal December 1974
Canopy Architecture and Turbulence Structure in a Coniferous Forest journal July 2003
Ecophysiological controls over the net ecosystem exchange of mountain spruce stand. Comparison of the response in direct vs. diffuse solar radiation journal January 2007
Environmental controls over carbon dioxide and water vapor exchange of terrestrial vegetation journal December 2002
A Two-Year Comparison of the Surface Water and Energy Budgets between Two OASIS Sites and NCEP–NCAR Reanalysis Data journal April 2004
Spatial distribution of carbon balance in forest ecosystems across East Asia journal May 2008
The impact of diffuse sunlight on canopy light-use efficiency, gross photosynthetic product and net ecosystem exchange in three forest biomes: IMPACT OF DIFFUSE SUNLIGHT ON CANOPY LUE, GPP AND NEE journal January 2007
Relationships between photosynthetically active radiation and clearness index at Bloemfontein, South Africa journal September 2004
Comparison of carbon dioxide fluxes over three boreal black spruce forests in Canada journal January 2007
Characterizing spatial representativeness of flux tower eddy-covariance measurements across the Canadian Carbon Program Network using remote sensing and footprint analysis journal September 2012
Assessing net ecosystem carbon exchange of U.S. terrestrial ecosystems by integrating eddy covariance flux measurements and satellite observations journal January 2011
Application of Akaike information criterion to evaluate warfarin dosing algorithm journal September 2010
The First Comprehensive Accuracy Assessment of GlobeLand30 at a National Level: Methodology and Results journal April 2015
Comparison of Akaike information criterion (AIC) and Bayesian information criterion (BIC) in selection of stock–recruitment relationships journal February 2006
Remote estimation of carbon dioxide uptake by a Mediterranean forest journal December 2008
Carbon and water fluxes over a temperate Eucalyptus forest and a tropical wet/dry savanna in Australia: measurements and comparison with MODIS remote sensing estimates journal April 2005
Partitioning energy and evapo-transpiration above and below a tropical palm canopy journal October 2006
Multi-site evaluation of terrestrial evaporation models using FLUXNET data journal April 2014
Open access to Earth land-cover map journal October 2014
Refining light-use efficiency calculations for a deciduous forest canopy using simultaneous tower-based carbon flux and radiometric measurements journal March 2007
Integration of MODIS land and atmosphere products with a coupled-process model to estimate gross primary productivity and evapotranspiration from 1 km to global scales: GLOBAL GPP AND ET journal December 2011
Predicting the onset of net carbon uptake by deciduous forests with soil temperature and climate data: a synthesis of FLUXNET data journal February 2005
Global land cover mapping at 30m resolution: A POK-based operational approach journal May 2015
Carbon exchange and venting anomalies in an upland deciduous forest in northern Wisconsin, USA journal November 2004
Ecosystem carbon fluxes and canopy spectral reflectance of a mountain meadow journal November 2008
Effective and efficient global optimization for conceptual rainfall-runoff models journal April 1992
Sustained carbon uptake and storage following moderate disturbance in a Great Lakes forest journal July 2013
Response of a Deciduous Forest to the Mount Pinatubo Eruption: Enhanced Photosynthesis journal March 2003
A Continuous Satellite-Derived Measure of Global Terrestrial Primary Production journal January 2004
Carbon sequestration in boreal jack pine stands following harvesting journal June 2009
Development of a semi-parametric PAR (Photosynthetically Active Radiation) partitioning model for the United States, version 1.0 journal January 2014
Global Primary Production: A Remote Sensing Approach journal July 1995
A theoretical analysis of nitrogen and radiation effects on radiation use efficiency in peanut journal January 1994
'Breathing' of the terrestrial biosphere: lessons learned from a global network of carbon dioxide flux measurement systems journal January 2008
Data-based perfect-deficit approach to understanding climate extremes and forest carbon assimilation capacity journal May 2014
Simple scaling of photosynthesis from leaves to canopies without the errors of big-leaf models journal May 1997
Carbon dioxide and energy fluxes from a boreal mixedwood forest ecosystem in Ontario, Canada journal November 2006
A Global Terrestrial Monitoring Network Integrating Tower Fluxes, Flask Sampling, Ecosystem Modeling and EOS Satellite Data journal October 1999
Estimation of carbon mass fluxes over Europe using the C-Fix model and Euroflux data journal December 2002
An integrated biosphere model of land surface processes, terrestrial carbon balance, and vegetation dynamics journal December 1996
Advantages of diffuse radiation for terrestrial ecosystem productivity: ADVANTAGES OF DIFFUSE RADIATION journal March 2002
Effects of short-term variation in weather on diurnal canopy CO2 flux and evapotranspiration of a juvenile douglas-fir stand journal April 1990
Estimation of net ecosystem carbon exchange for the conterminous United States by combining MODIS and AmeriFlux data journal October 2008
Partitioning European grassland net ecosystem CO2 exchange into gross primary productivity and ecosystem respiration using light response function analysis journal June 2007
Management effects on European cropland respiration journal November 2010
Interacting controls on productivity in a northern Great Plains grassland and implications for response to ENSO events: CONTROLS ON GRASSLAND PRODUCTIVITY journal June 2011
The net biome production of full crop rotations in Europe journal November 2010
The carbon budget of newly established temperate grassland depends on management intensity journal June 2007
Global estimates of evapotranspiration and gross primary production based on MODIS and global meteorology data journal July 2010
Instantaneous Measurement of Radiation and Water Use Efficiencies of a Maize Crop journal January 1996
Experimental design for flux measurements: matching scales of observations and fluxes journal November 1997
Some Comments on the Evaluation of Model Performance journal November 1982
Sensitivity of Moderate Resolution Imaging Spectroradiometer (MODIS) terrestrial primary production to the accuracy of meteorological reanalyses journal January 2006
Modelling canopy CO 2 fluxes: are ‘big-leaf’ simplifications justified? journal November 2001
Impact of severe dry season on net ecosystem exchange in the Neotropical rainforest of French Guiana journal August 2008
The annual cycles of CO2 and H2O exchange over a northern mixed forest as observed from a very tall tower journal September 2003
Predicting gross primary production from the enhanced vegetation index and photosynthetically active radiation: Evaluation and calibration journal December 2011
Boundary Layer Clouds and Vegetation–Atmosphere Feedbacks journal January 2001
Carbon Dioxide Exchange between an Undisturbed Old-Growth Temperate Forest and the Atmosphere journal January 1994
An eddy covariance mesonet to measure the effect of forest age on land?atmosphere exchange journal November 2006
Biophysical controls on CO 2 fluxes of three Northern forests based on long-term eddy covariance data journal April 2008
Comparison of NCEP-NCAR Reanalysis with 1987 FIFE Data journal July 1996
Estimating Gross Photosynthesis Using Satellite and Ancillary Data Approach and Preliminary Results journal January 2001
Radiation and water use efficiencies of two coniferous forest canopies journal October 1996
Evaluation of cropland maximum light use efficiency using eddy flux measurements in North America and Europe: CROPLAND MAXIMUM LIGHT USE EFFICIENCY journal July 2011
A new mass conservation approach to the study of CO 2 advection in an alpine forest journal January 2009
On the Validation of Models journal July 1981
Estimating daily gross primary production of maize based only on MODIS WDRVI and shortwave radiation data journal December 2011
Physiological responses of a black spruce forest to weather journal December 1997
Impact of atmospheric aerosol light scattering and absorption on terrestrial net primary productivity: IMPACT OF AEROSOLS ON NET PRIMARY PRODUCTIVITY journal November 2002
Vegetation Index Methods for Estimating Evapotranspiration by Remote Sensing journal October 2010
Patterns and controls of the variability of radiation use efficiency and primary productivity across terrestrial ecosystems: Global patterns in radiation use efficiency and photosynthetic uptake journal December 2009
Overview of ChinaFLUX and evaluation of its eddy covariance measurement journal April 2006
Towards a standardized processing of Net Ecosystem Exchange measured with eddy covariance technique: algorithms and uncertainty estimation journal January 2006
Response of carbon fluxes to drought in a coastal plain loblolly pine forest: DROUGHT AND CARBON FLUXES IN A COASTAL PLAIN FOREST journal January 2010
Preliminary analysis of spatiotemporal pattern of global land surface water journal August 2014
Effects of diffuse radiation on canopy gas exchange processes in a forest ecosystem: DIFFUSE RADIATION EFFECTS IN FOREST journal May 2008
Variation in Crop Radiation-Use Efficiency with Increased Diffuse Radiation journal January 1992
Parameter estimation in surface exchange models using nonlinear inversion: how many parameters can we estimate and which measurements are most useful? journal May 2001
Evaluation of satellite and reanalysis products of downward surface solar radiation over East Asia: Spatial and seasonal variations: EVALUATION OF DSSR OVER EAST ASIA journal May 2013
On the separation of net ecosystem exchange into assimilation and ecosystem respiration: review and improved algorithm journal September 2005
Seasonality of ecosystem respiration and gross primary production as derived from FLUXNET measurements journal December 2002
Modeling gross primary production of temperate deciduous broadleaf forest using satellite images and climate data journal May 2004
Reduced carbon sequestration in terrestrial ecosystems under overcast skies compared to clear skies journal September 2008
A comprehensive set of benchmark tests for a land surface model of simultaneous fluxes of water and carbon at both the global and seasonal scale journal January 2011
Measuring and modelling carbon dioxide and water vapour exchange over a temperate broad-leaved forest during the 1995 summer drought journal September 1997
Separation of net ecosystem exchange into assimilation and respiration using a light response curve approach: critical issues and global evaluation: SEPARATION OF NEE INTO GPP AND RECO journal January 2010
Seasonal and annual variations in the photosynthetic productivity and carbon balance of a central Siberian pine forest journal November 2002
Daily canopy photosynthesis model through temporal and spatial scaling for remote sensing applications journal December 1999
Ecosystem-level CO2 fluxes from a boreal cutover in eastern Canada before and after scarification journal November 2006
Measurements necessary for assessing the net ecosystem carbon budget of croplands journal November 2010
Calibration of Terra/MODIS gross primary production over an irrigated cropland on the North China Plain and an alpine meadow on the Tibetan Plateau: CALIBRATION OF TERRA/MODIS GROSS PRIMARY PRODUCTION journal January 2008
A comparative analysis of simulated and observed photosynthetic CO2 uptake in two coniferous forest canopies journal July 2006
Terrestrial ecosystem production: A process model based on global satellite and surface data journal December 1993
Random and systematic CO2 flux sampling errors for tower measurements over forests in the convective boundary layer journal January 2009
Global pattern of NPP to GPP ratio derived from MODIS data: effects of ecosystem type, geographical location and climate journal May 2009
Productivity, Respiration, and Light-Response Parameters of World Grassland and Agroecosystems Derived From Flux-Tower Measurements journal January 2010
Solar Radiation and Productivity in Tropical Ecosystems journal December 1972
Deriving a light use efficiency model from eddy covariance flux data for predicting daily gross primary production across biomes journal April 2007
Incorporating diffuse photosynthetically active radiation in a single-leaf model of canopy photosynthesis for a 56-year-old Douglas-fir forest journal January 2009
FLUXNET: A New Tool to Study the Temporal and Spatial Variability of Ecosystem–Scale Carbon Dioxide, Water Vapor, and Energy Flux Densities journal November 2001
Soybean Radiation-Use Efficiency as Influenced by Nonuniform Specific Leaf Nitrogen Distribution and Diffuse Radiation journal January 1993
Evaluation of MODIS NPP and GPP products across multiple biomes journal June 2006
The MODIS (Collection V005) BRDF/albedo product: Assessment of spatial representativeness over forested landscapes journal November 2009
Stimulation of both photosynthesis and respiration in response to warmer and drier conditions in a boreal peatland ecosystem: PEATLAND CARBON DIOXIDE EXCHANGE journal January 2011
Direct and indirect effects of atmospheric conditions and soil moisture on surface energy partitioning revealed by a prolonged drought at a temperate forest site journal January 2006
Assessing parameter variability in a photosynthesis model within and between plant functional types using global Fluxnet eddy covariance data journal January 2011
Disentangling leaf area and environmental effects on the response of the net ecosystem CO 2 exchange to diffuse radiation journal January 2008
Relationship between gross primary production and chlorophyll content in crops: Implications for the synoptic monitoring of vegetation productivity journal January 2006
Large carbon uptake by an unmanaged 250-year-old deciduous forest in Central Germany journal September 2003
Measuring fluxes of trace gases and energy between ecosystems and the atmosphere - the state and future of the eddy covariance method journal June 2014

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Related Subjects

54 ENVIRONMENTAL SCIENCES
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
FLUXNET
MODIS
gross primary productivity
sunlit and shaded leaves
two-leaf light use efficiency model