Measuring hydraulic traits in Quercus ilex is particularly challenging because the species has long xylem vessels, faces regularly low water potential values and is particularly resistant to xylem cavitation. A new effort to tackle methodological issues and get a better understanding of hydraulic functioning in this species is conjointly lead by researchers from the INRA URFM in Avignon, the CEFE CNRS in Montpellier and the INRA PIAF in Clermont-Ferrand. Quercus ilex branches collected at the two experimental sites of Puéchabon and Font-Blanche were brought to the PIAF lab in Clermont-Ferrand and measured with the latest state-of-the-art techniques in plant hydraulics. Leaf hydraulic conductance by rehydration, leaf vulnerability to cavitation by optical scanning, branch native embolism by X-ray tomography, leaf cuticular conductance by dehydration and acoustic detection of xylem cavitation were all tested and measured during one week using the facilities and instruments of the PIAF. The promising results obtained during this campaign will improve our understanding of Quercus ilex resistance to the extreme drought events that the trees experienced in 2016 and 2017 at the two sites of Font-Blanche and Puéchabon.
