Differences in wood properties between juvenile wood and mature wood in 10species grown in China

This study examined the intrinsic differences in various wood properties be tween juvenile wood and mature wood in 10 major reforestation species in Ch ina. Comparisons between juvenile wood and mature wood were made in both pl antation- and naturally-grown trees. Considerable differences in most wood properties were found both between plantation-grown juvenile wood and matur e wood, and between naturally-grown juvenile wood and mature wood. This sug gests that wood properties of plantation-grown trees, to a large extent, de pends on their juvenile wood contents, and can thus be manipulated effectiv ely through rotation age. In general, the longer the rotation age, the lowe r the juvenile wood content, and the stronger the mechanical properties of the plantation-grown woods. However, the differences between juvenile wood and mature wood vary with wood properties and species. In general, juvenile wood and mature wood have less difference in chemical composition than in anatomical and physicomechanical properties. Compared to the softwoods stud ied, the hardwoods appear to have less difference between juvenile wood and mature wood.