[en] A sensitivity analysis of a proposed parameterization of the stomatal conductance (g_s) module of the European ozone deposition model (DO₃SE) for Quercus ilex was performed. The performance of the model was tested against measured g_s in the field at three sites in Spain. The best fit of the model was found for those sites, or during those periods, facing no or mild stress conditions, but a worse performance was found under severe drought or temperature stress, mostly occurring at continental sites. The best performance was obtained when both f_phen and f_SWP were included. A local parameterization accounting for the lower temperatures recorded in winter and the higher water shortage at the continental sites resulted in a better performance of the model. The overall results indicate that two different parameterizations of the model are needed, one for marine-influenced sites and another one for continental sites. - No redundancy between phenological and water-related modifying functions was found when estimating stomatal behavior of Holm oak