Knots properties of lodgepole sawn boards from unthinned stands planted in different initial spacings : case study from northern Sweden

Abstract: The objective of this study was to assess quality of lodgepole pine (Pinus contorta Dougl. var. latifolia) sawn boards derived from stands established in four different initial densities i.e. 1.1 m x 1.1m, 2.0 m x 2.0 m, 2.85 m x 2.85 m, 4.0 m x 4.0 m. The logs were extracted from unthinned plots that were 44-years-old growing in northern Sweden. The quality was assessed in respect to knots properties as knot size, knots number, position on the board, living status of the knot ect. It was found that wood quality regarding mean knot size and knot are ratio (KAR) was decreasing with growing space availability. There were no differences between spacings in terms of knot frequency. There was also no evidence of differences in knot type variation between the treatments. Thus, conventional spacing of 2.0 m x 2.0 m (2500 seedlings ha⁻¹) seems to be a reasonable compromise between timber quality, economics and growth. However, there is a potential to decrease planting densities without depreciation of knots parameters.