Frost crack impact on European beech (Fagus sylvatica L.) wood quality

Abstract

Frost crack represents one of the main defects which affect European beech wood quality. Therefore, the purpose of this paper is to improve the knowledge regarding both the impact of frost crack on European beech wood quality and the frost crack characteristics which affect wood quality. In order to do this, nineteen European beech trunks with frost crack have been studied. Each trunk has been cross-cut every 1 meter and the characteristics of frost crack and frost crack star-shaped heart have been measured in each cross-cut section. The defects which accompany frost crack have also been identified in each crosscut section. Moreover, the possibility of determining these defects using the IML RESIF500 - S Resistograph has been tested. The research has emphasized the existence of statistical correlations between frost crack star-shaped heart expansion, frost crack rib prominence and frost crack length. These correlations are expressed by multiple linear regressions. The presence of defects which affect wood structure leading to a decrease in penetration resistance can be determined accurately with the resistograph. Decay (in frost cracks older than 8 years) and ring shake have been identified as the most frequent defects which accompany frost crack. The measurements made on the frost cracks studied have been gathered in a graph which shows frost crack impact on European beech wood quality. The results obtained lead to the improvement of the criteria of European beech wood quality assessment by expanding the already existent knowledge and by identifying new aspects which may complete standing wood quality determination and sorting methods.