The effect of shoot architecture on hydraulic conductance in beech (Fagus sylvatica L.)

Shoot hydraulic conductance was measured in beech (Fagus sylvatica L.) that had previously been ex; posed to high levels of nitrogen input. Whole-shoo t hydraulic conductance, conductance per unit pressure gradient and leaf sp ecific conductance were negatively correlated with the number of bud scars per unit length, a morphological parameter of tree decline. We propose a ne gative feedback mechanism by which stress induced alterations in shoot morp hology can cause a lasting reduction of tree vigour.