Effects of thinning on basic density and tracheid length of karamatsu (Larix leptolepis)

The purpose of this study as to determine the effects of thinning on intrinsic wood properties of karamatsu (Lalix leptolepis Gord.) trees in plantations. Woods obtained from heavily, lightly, and unthinned plots were examined to determine the relationships between basic densities and tracheid lengths, and thinning treatments. Thinning treatments, especially heavy thinning treatment, accelerated volume increment and diameter growth. Latewood percentages were not affected significantly by any of the thinning treatments because of the relatively increases in latewood widths with increases in annual ring widths after thinning treatments. As a result, basic density also was not affected significantly by any of the thinning treatments. Latewood tracheid lengths decreased after heavy thinning treatments. On the other hand, tracheid lengths were not affected by light thinning treatments.