Analysis of Qualitative Features of Beech and Oak Trunks as a Determinant of the Quality Assessment

Proper quality assessment of timber requires a certain level of knowledge and overview of technical conditions and correct identification and assessment of the qualitative features of trunks. The ratio of the highest quality classes is decreasing. Therefore, increasing the potential financial resources allocated to forest management could lead to the improvement and increase of this ratio. The objective of the study was to identify the frequency and occurrence of limiting features in the group of non-coniferous beech and oak trunks. A further objective was to classify major factors causing and increasing the frequency of occurrence of such limiting marks. Altogether, 969 beech and oak trunks were assessed in the University Forest Enterprise of the Technical University in Zvolen. The dependences of the size and occurrence of individual qualitative features on the selected factors were statistically assessed using the Pearson correlation coefficient and Cramer’s V; significance was established using χ² test and a significance level α = 0.05. The most frequently occurring features were sweep, knots, and heart shakes. The results of the comparative and statistical analysis indicate that the management of forest stands and interventions carried out in the forest stands affect the occurrence of the negative features being analyzed the most. However, the conditions of the given site (soil, subsoil, and slope) also play a certain role and can affect the technological aspect of the harvest. The obtained results are valid for the conditions of the University Forest Enterprise of the Technical University in Zvolen; however, they can also be applied in a wider range of similar conditions of Central European forest stands.