Delayed effect of drought on the xylem vulnerability to embolism in Fagus sylvatica.

Understanding the variation in drought resistance traits is needed to predict the potential of trees to adapt to severe drought events. Xylem vulnerability to embolism is a critical trait related to drought-induced mortality with a large variability between species. Acclimation of this trait to environmental conditions implies changes in the xylem structure and organization, leading previous studies to investigate its variations under conditions preserving growth. In European beech saplings, we assessed the effect of droughts on the vulnerability to embolism in branches developed the next year during recovery. The newly formed branches displayed lower vulnerability to embolism in the plants that underwent the severest droughts leading to native embolism; the pressure that induces 50% loss of conductance being of -3.98 MPa in severely droughted plants whereas it was of 3.1 MPa in control plants, respectively. These results argue for a lagged acclimation of this trait to drought events.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author