The watering of tall trees. Embolization and recovery

 Séminaire IUSTI

Henry Gouin

Professeur émérite, M2P2

Résumé : We can propound a thermo-mechanical understanding of the ascent of sap to the top of tall trees thanks to a comparison between experiments associated with the cohesion-tension theory and the disjoining pressure concept for liquid thin-films. When a segment of xylem is tight-filled with crude sap, the liquid pressure can be negative although the pressure in embolized vessels remains positive. Examples are given that illustrate how embolized vessels can be refilled and why the ascent of sap is possible even in the talles trees avoiding the problem due to cavitation. However, the maximum height of trees is limited by the stability domain of liquid thin-films.

Date et lieu : le Vendredi 9 Octobre 2015 à 11h00, salle 250 IUSTI