VARIATION OF WOOD ACIDITY IN HARD- AND SOFTWOODS DURING STORAGE UP TO ONE YEAR

Abstract

The effect of the storage on the wood acidity was investigated by storing of fresh wood chips from two angiosperm and two gymnosperm species Lip to one year. Cold water-, hot water- and enhanced acidity in acetate and phosphate solutions were determined titrimetrically at certain intervals during one year. The study demonstrated considerable differences in the speed at which the acids were liberated from various species. On the first day, just after trees were felled, cold water acidity of woods was significantly higher than hot water acidity and this is an unusual event. After five days, cold water and hot water acidity of hardwoods decreased, but their values in softwoods changed cycle-wise with certain intervals. A sudden decrease in all kind of acidities was observed in the 6th month and all species had the lowest value at this time. Except ash wood, acetate- and phosphate acidity of other species showed a slightly increase on the seasoning of chips until 6th month. The ash wood behaved somewhat differently compared to other species. Cold water, acetate- and phosphate acidities in this wood exhibited a progressive decrease until 6th month of the storage.