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TitleAssessment of canopy stomatal conductance models using flux measurements
AuthorWang, S; Yang, Y; Trishchenko, A P
SourceEcological Modelling vol. 220, 2009 p. 2115-2118,
Alt SeriesEarth Sciences Sector, Contribution Series 20090074
File formatpdf
Subjectsenvironmental geology; soils science; remote sensing; vegetation; terrain inventories; terrain types; soil classification; soil types
Illustrationshistograms; plots; tables
ProgramEarth Science for National Scale Characterization of Climate Change Impacts on Canada's Landmass, Climate Change Geoscience
AbstractStomatal conductance (g) is a key parameter in controlling energy and water exchanges between canopy and the atmosphere. Stomatal conductance models proposed by Ball, Woodrow and Berry (BWB) and Leuning have been increasingly used in land surface schemes. In a recent study, a new diagnostic index was developed byWang et al. to examine the response of g to humidity and new models were proposed to resolve problems identified in the BWB and Leuning models. This approach is theoretically sound, but relies on canopy latent heat and CO2 fluxes and environmental variables at the leaf surface which are not available at most eddy correlation (EC) observation sites. In this study, we tested the diagnostic index by empirically correcting EC measurements to canopy-level fluxes and by replacing leaf surface variables by their corresponding ambient air variables, and re-examined the stomatal conductance models of BWB, Leuning, and Wang et al. We found that the impact of the above modifications on the evaluation of g-humidity relationships is very small. This study provides apractical approachto investigate the stomatal response to humidity using routine EC measurements.