Modelling ozone stomatal flux of wheat under mediterranean conditions

Correct estimation of leaf-level stomatal conductance (gsto) is central for current ozone (O3) risk assessment of wheat yield loss based on the absorbed O3 phytotoxic dose (POD). The gsto model parameterizations developed in Europe must be checked in the different climatic regions where they are going to be applied in order to reduce the uncertainties associated with the POD approach.This work proposes a new gsto model parameterization for estimating POD of Triticum aestivum and Triticum durum under Mediterranean conditions, based on phenological observations over 25 years and gsto field measurements during 5 growing seasons. Results show that POD in the Mediterranean area might be higher than previously estimated. However, caution must be paid when assessing the risk of yield loss for wheat in this area since field validation of O3 impacts is still limited.

► Models to estimate ozone deposition flux need to be tested in the field.
► A new ozone flux model parameterization for Mediterranean wheat is proposed.
► Modelled ozone flux for Mediterranean wheat was higher than previously estimated.
► Regional model parameterizations are more suitable for ozone risk assessment.
► Field validation of ozone effects on wheat yield in Southern Europe is still scarce.