Modelling stomatal conductance of wheat: An assessment of response relationships under elevated CO2

Research output: Contribution to journalArticlepeer-review


  • Alireza Houshmandfar
  • Glenn J. Fitzgerald
  • Roger Armstrong
  • Allene A. Macabuhay
  • Michael Tausz

Colleges, School and Institutes

External organisations

  • The University of Melbourne, Australia
  • Transport and Resources


This study proposes Jarvis-type model parameterisations for estimating stomatal conductance (gs) in wheat (Triticum aestivum L.) under ambient [CO2] (a[CO2], approximately 390μmolmol-1) and elevated [CO2] (e[CO2], approximately 550μmolmol-1), based on measurements collected in the Australian Grains Free Air CO2 Enrichment (AGFACE) facility. Relationships of gs with phenological and environmental factors were evaluated using a boundary line technique. Results suggest that gs-response functions for vapour pressure deficit (VPD), volumetric soil moisture (VSM) and temperature dependence were different between a[CO2] and e[CO2]: VPD induced stomatal closure at approximately 3 and 2.5kPa under a[CO2] and e[CO2] respectively, and optimum temperature was 2°C lower under e[CO2]. Elevated [CO2] decreased maximum gs (gmax) by approximately 35%.


Original languageEnglish
Pages (from-to)117-123
Number of pages7
JournalAgricultural and Forest Meteorology
Early online date24 Aug 2015
Publication statusPublished - 15 Dec 2015


  • Humidity, Jarvis model, Soil moisture, Transpiration, Triticum aestivum, Vapour pressure deficit