Determining the quality of aspen (Populus tremula) logs for mechanical wood processing in Finland

摘要

The quality of aspen logs (Populus tremula) was studied by sawing sample logs. For grading of aspen logs and sawn timber, the proposed system of Keinanen et al. (1995) plus the reject-grade was used. The length of the knot-free section at the base of an aspen stem is short. Green knots are concentrated in the top logs and red knots at the top of the butt logs and first middle logs. Most of the decayed knots are located in the second middle logs and top logs. The most common reasons for decreasing quality grade were rot and knots. The yield from aspen timber is best when relatively short components of sawn wood can be utilized. Regression models are presented for predicting the value of aspen logs. Lumber cutting length in the lumber grading criteria had the largest effect on grade yields and monetary values of the aspen logs.