Identifying beech round wood quality - distribution of beech timber qualities and influencing defects

Abstract

The classification of round wood depends on the defects and other morphological features of a tree trunk.Various tree species growing on different forest sites and in different conditions eventually present a wood quality influenced by said factors.The objective of this paper was to find out: 1) the distribution of round wood quality classes of beech in three different site conditions and 2) the frequency of the defects influencing timber grading.The research was carried out on 15 different sample plots of three site quality classes, on which 1389 beech logs were classified according to the existing grading scheme.The most common timber quality (by volume) was WC0 and then in decreasing order: WD, WB0 and WA0, in proportions of: 15:10:4:1.This order was the same for the assortments obtained from the trees in all the analysed site quality classes.The most frequent defects influencing wood quality were knots, among which sound knots were in the majority.The proportion of the appearance of knots was 7:3:2 for sound knots, unsound and dead knots, as well as covered knots, respectively.Sweep, red heart and scars were of a similar frequency to sound knots, approx.20%.Double pith, shakes, rot, top diameter and spiral grain were of a minor influence on WQCs and together amounted to approx.10% of the frequency among other defects.