Electical migration of exogenous mineral ions through green sapwood of Pinus sylvestris L. (Scots pine)

The electrical migration was studied of several cations passing longitudinally through cylindrical samples of green sapwood of Pinus sylvestris L. under the influence of an applied electric field. This led to values for the hindered ionic conductances within the wood of the cations Li+, K+ and Cu2+ which were compared with data obtained previously (Simons et al., 1998) for several endogenous cations. There was satisfactory agreement for the conductance of the potassium ion, the only one to be determined by both methods. Copper ions were found to possess a higher conductance within the wood than calcium or magnesium, a factor relevant to its use as a wood preservative. Visual observation of the location of the blue-green colouration produced in the wood by copper ions indicated that they migrated via longitudinal resin ducts and tracheids. Elution and transport experiments were also carried out with sapwood which had been flushed with water, Li2SO4 or CuSO4 solution.