Xylem hydraulic conductivity: a complex elastic micro porous media that promote and sustain tree live.

VICTOR A. KUZ; ARIEL G. MEYRA; GUILLERMO J. ZARRAGOICOECHEA

Viña del Mar, Chile

Workshop; Twelfth International Workshop on Instabilities and Nonequilibrium Structures; 2009

<!-- @page { size: 8.5in 11in; margin: 0.79in } P { margin-bottom: 0.08in } --> Tensions in the liquid water inside conducting xylem elements lead to cavitation. The resistance of conduits against cavitation and embolization are usually analyzed by constructing vulnerability curves. Via a dimensional analysis and considering cavitation as a limited growth process, it is obtained a dimensionless Verhulst differential equation. A sigmoidal function with only one control parameter, a dimensionless number, is a self similar solution of this equation. This number evidences the relation between function and structure of the xylem system. Vulnerability is regulated by intrinsic properties of xylem conducting elements as it is the capillary flow in a porous elastic media.