Pressure–volume curves of shoots and roots of normal and drought conditioned western hemlock seedlings

Abstract

Pressure–volume curves for western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings showed roots to have lower osmotic potentials, at both full turgor and incipient plasmolysis, and lower relative water contents at incipient plasmolysis than shoots. Roots remained turgid under mild water deficit, whereas shoots lost turgor exponentially with water content. Shoots of seedlings given a 2-week drought stress had lower osmotic potentials at full turgor and incipient plasmolysis than shoots of unstressed seedlings; roots showed a similar trend.