Reconciling the optimal and empirical approaches to modelling stomatal conductance

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Show simple item record Medlyn, BE Duursma, RA Eamus, D Ellsworth, DS Prentice, IC Barton, CVM Crous, KY De Angelis, P Freeman, M Wingate, L 2012-10-12T03:33:16Z 2011-06
dc.identifier.citation Global Change Biology, 2011, 17 (6), pp. 2134 - 2144
dc.identifier.issn 1354-1013
dc.identifier.other C1 en_US
dc.description.abstract Models of vegetation function are widely used to predict the effects of climate change on carbon, water and nutrient cycles of terrestrial ecosystems, and their feedbacks to climate. Stomatal conductance, the process that governs plant water use and carbon uptake, is fundamental to such models. In this paper, we reconcile two long-standing theories of stomatal conductance. The empirical approach, which is most commonly used in vegetation models, is phenomenological, based on experimental observations of stomatal behaviour in response to environmental conditions. The optimal approach is based on the theoretical argument that stomata should act to minimize the amount of water used per unit carbon gained. We reconcile these two approaches by showing that the theory of optimal stomatal conductance can be used to derive a model of stomatal conductance that is closely analogous to the empirical models. Consequently, we obtain a unified stomatal model which has a similar form to existing empirical models, but which now provides a theoretical interpretation for model parameter values. The key model parameter, g1, is predicted to increase with growth temperature and with the marginal water cost of carbon gain. The new model is fitted to a range of datasets ranging from tropical to boreal trees. The parameter g1 is shown to vary with growth temperature, as predicted, and also with plant functional type. The model is shown to correctly capture responses of stomatal conductance to changing atmospheric CO2, and thus can be used to test for stomatal acclimation to elevated CO2. The reconciliation of the optimal and empirical approaches to modelling stomatal conductance is important for global change biology because it provides a simple theoretical framework for analyzing, and simulating, the coupling between carbon and water cycles under environmental change. © 2011 Blackwell Publishing Ltd.
dc.language eng
dc.relation.hasversion Accepted manuscript version en_US
dc.relation.isbasedon 10.1111/j.1365-2486.2010.02375.x
dc.title Reconciling the optimal and empirical approaches to modelling stomatal conductance
dc.type Journal Article
dc.parent Global Change Biology
dc.journal.volume 6
dc.journal.volume 17
dc.journal.number 6 en_US
dc.publocation Malden en_US
dc.identifier.startpage 2134 en_US
dc.identifier.endpage 2144 en_US SCI.Faculty of Science en_US
dc.conference Verified OK en_US
dc.for 0502 Environmental Science and Management
dc.personcode 000006
dc.personcode 995746
dc.percentage 100 en_US Environmental Science and Management en_US
dc.classification.type FOR-08 en_US
dc.edition en_US
dc.custom en_US en_US
dc.location.activity WOS:000289641400010 en_US
dc.description.keywords Coupled conductance and photosynthesis models
dc.description.keywords Marginal water cost of carbon
dc.description.keywords Stomatal conductance
dc.description.keywords Stomatal optimization
pubs.embargo.period Not known
pubs.organisational-group /University of Technology Sydney
pubs.organisational-group /University of Technology Sydney/Faculty of Business
pubs.organisational-group /University of Technology Sydney/Faculty of Science
utslib.copyright.status Open Access 2015-04-15 12:23:47.074767+10
pubs.consider-herdc true
utslib.collection.history General (ID: 2)
utslib.collection.history School of the Environment (ID: 344)

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