A new approach for the limit to tree height using a liquid nanolayer model

TL;DR

This paper introduces a liquid nanolayer model that explains how thin liquid films can sustain high altitudes in trees, surpassing traditional incompressible fluid predictions, thus shedding light on the maximum height of trees like sequoias.

Contribution

It presents a novel nanolayer model accounting for intermolecular forces and density gradients, providing insights into the limit of tree height and sap ascent mechanisms.

Findings

Stable thin liquid films can exist at higher altitudes than predicted by classical models.

The model explains sap ascent in very tall trees like sequoias.

Intermolecular forces enable liquid stability in microtubes of xylem.

Abstract

Liquids in contact with solids are submitted to intermolecular forces inferring density gradients at the walls. The van der Waals forces make liquid heterogeneous, the stress tensor is not any more spherical as in homogeneous bulks and it is possible to obtain stable thin liquid films wetting vertical walls up to altitudes that incompressible fluid models are not forecasting. Application to micro tubes of xylem enables to understand why the ascent of sap is possible for very high trees like sequoias or giant eucalyptus.