Factors affecting the healing-over of pruned Scots pine knots.
The material of the study consisted of 21 Scots pine (Pinus sylvestris L.) trees that had been pruned in the 1930’s and 1940’s. The butt log of the pruned stems was peeled into veneer from which the length and shape of the resin taps were determined. The length of the resin tap was affected in the first place by the knot diameter and the height of the knot along the stem. The length of the resin tap was about 1.5-fold that of the knot diameter. With an increase in the height above the ground of a knot, its length decreases. The resin taps were particularly long on poor sites and in the butt end of the stems, however, the variation in tap length was large both within and between the individual tree stands. The shape of the resin taps is presented in this study by diameter classes. The resin taps studied in the work were longer than those measured in other works. This may be due to the fact that the knots were uncovered by peeling instead of sawing.
The PDF includes an abstract in Finnish.
Published in 1989