
%0 Journal Article
%A Leuning, R 
%T Modelling Stomatal Behaviour and and Photosynthesis of <I>Eucalyptus grandis</I>
%J Functional Plant Biology
%D 1990/04/01
%V 17
%N 2
%P 159-175
%K 
%R https://doi.org/10.1071/PP9900159
%U https://www.publish.csiro.au/paper/PP9900159 
%X Stomatal conductances, CO2 assimilation, transpiration and intercellular CO2 mol fractions of Eucalyptus grandis leaves were measured in the field using a portable, controlled environment cuvette. Test leaves were subjected to a range of temperatures, humidities, photon irradiances and external CO2 mol fractions. An empiral function, gsw = g0 + g1 Ahs/(cs-I'), was able to account for steady- state stomatal conductances g*sw, over a wide range of environmental conditions and leaf photosynthetic capacities. In this equation, termed the stomatal constraint function, A is CO2 assimilation rate, hs and cs are relative humidity and CO2 mol fraction at the leaf surface respectively, I' is the CO2 compensation point, g0 is conductance at A = 0 and gl is an empirical coefficient. Equations describing the supply of CO2 through stomata and demand for CO2 in photosynthesis were solved simultaneously with the constraint function to give a combined model of stomatal conductance, CO2 assimilation and intercellular CO2 mol fraction in terms of external environmental factors and several parameters describing C3 photosynthesis. The model provided a good description of experimental observations. 
