Study of the position of pitch pockets in the tree trunk of the Dahurian larch
The article deals with the study of the position of pitch pockets in Dahurian larch tree trunk. It describes field research on defect of wood structure with a view to collecting statistical data, its analysis and obtaining mathematical dependences with morphological parameters of the tree for subsequent use of data in mathematical modeling when solving the problems of optimization of output of lumber and wood products industry. The article substantiates the research on data collection on the position and size of pitch pockets in Dahurian larch tree trunk to find the optimal cutting of logs for obtaining sawn wood of higher quality. The author gives a consistent and detailed description of the research method. The analysis of the requirements for the defect of the main Russian and international quality standards for soft timber serves as the basis for this research. The process of necessary data collection is illustrated step by step in the article. The results of the research of pitch pockets in Dahurian larch tree trunk are analyzed in detail. The dependence of the pockets' position on qualitative zones of the trunk, as well as on the main morphological parameters of tree trunk, is determined. The boundaries of pockets accumulation along the thickness and length of the tree trunk are calculated. As a result of the research, the same number of the pockets from the northern and southern sides of the core cut has been identified. More than half of the found pockets were in the areas that included other defects of wood structure. The most pronounced dependency is revealed in the areas of inferior wood, the boundaries of the transition from sound to sapwood and from sapwood to bastwood.