Water Uptake in Deciduous Trees During Winter and the Role of Conducting Tissues in Spring Reactivation

In winter, deciduous trees lack any means for transpiration, nevertheless their buds swell and increase in weight. It is known that vessels play an important role in spring reactivation and that phloem may be involved since buds fail to break when twigs are ringed. This study investigates water/nutrient translocation from winter until reactivation in spring for five North European species: maple ( Acer pseudoplatanus L.), birch ( Betula pendula Roth), alder ( Alnus glutinosa Gaertn.), beech ( Fagus sylvatica L.), and ash ( Fraxinus excelsior L.). Accordingly emphasis is laid on the relative timing of onset of water conduction among the species.