New evidences relating the seasonal evolution of maximum daily trunk shrinkage with xylem vulnerability to embolism

Abstract

The interesting species specific relationship between maximum daily shrinkage and stem water potential (lPstem) was investigated in order to understand the potential mechanisms involved. Despite of the known correlation with the range of ~stem at which stomata exerts the control of transpiration, a new correlation was obtained with the air entry ~stem of the xylem in the studied species. Results of this study reinforce the idea of a tight correlation among plant capacitance, transpiration and maintenance of water status of the plant. These results could confirm the hypothesis than xylem wood plays a central role in both refilling of water reservoirs and as an important reservoir itself, as it has been recently proposed.