Modelling leaf gas exchange in holm-oak trees in southern Spain

This paper presents a mechanistically based C-3 leaf CO2 assimilation model linked with an empirical stomatal model to simulate Quercus ilex leaf net photosynthesis and transpiration in oak-savannah ecosystems of southern Spa in. The model estimates (time integration) daily and seasonal changes in ca rbon fixation, transpiration, and water use efficiency of a single leaf in free air. Simulations were carried out on two trees for a dry year. Results shown in our study demonstrate that the modelling approach, compared to fi eld measurements, provides a realistic description of diurnal and seasonal patterns of leaf gas-exchange response to different environmental condition s, and as affected by water availability. (C) 1999 Elsevier Science B.V. Al l rights reserved.