Use of pressure volume curves in water relation analysis on woody shoots: influence of rehydration and comparison of four European oak species

Abstract

Pressure volume analyses were undertaken on lationship between leaf water potential, average osmotic potential and volume averaged tur- gor. Some technical limitations of pressure volume analysis, as shown by the influence of the resaturation method on intercellular water during the first stages of dehydration. Variations in leaf to stem ratio, which are very important between large leaved oaks and small leaved evergreens, surprisingly did not influence the relative symplasmic volume of our potential at full turgor (Π species, and to leaf age and growing conditions. Values of volumetric modulus of elasticity (ϵ 0 o appeared to be related more to the ability to osmotically adjust in response to changes in environment rather than to the absolute values of Π ) did not significantly influence the relations between leaf water potential (Ψ (P) in different species. This relationship was mostly related to Π 0 .