Effect of Growth Ring Width and Latewood Content on Selected Physical and Mechanical Properties of Plantation Japanese Larch Wood

In order to evaluate the physical and mechanical properties of plantation Japanese larch wood, various physical and mechanical indicators were measured with reference to Chinese national standards. The characteristics of the growth ring on the end face of wood samples were captured, with the mean latewood percentage being 21.4% and the mean ring width being 3.24 mm. Relationships between growth ring characteristics, latewood percentages, and the physical and mechanical properties of the plantation Japanese larch wood were investigated. The results revealed that it is most appropriate to use growth ring width to evaluate MOE and MOR, and to use latewood percentage to evaluate air-dry density, radial air-dry shrinkage, IBS and UTS. Regression analysis confirmed that air-dry density (R-2 = 0.99), radial shrinkage (R-2 = 0.97) and UTS (R-2 = 0.96) had significant positive correlations with latewood percentage, while MOE (R-2 = 0.88) and MOR (R-2 = 0.90) had significant negative correlations with RW. IBS was not significantly related to either characteristic. RW can be used to define juvenile wood and mature wood, with the dividing ring width being 4.85 mm. There is a large difference in MOE and MOR between the two wood types.