Wood Quality of Populus nigra × maxmowiczii. (I) - Variation of Bulk Density, Wood Fiber Dimension, Microfibril Angle, and Number of Leaf Knot within Stem -

양황철나무의 재질(材質) (I) 용적밀도수(容積密度數), 목섬유(木纖維)치수 및 잎옹이 분포수(分布數)의 간내변수(幹內變數) -

To study the wood quality factors of Populus nigra $\times$ maxmowiczii known a rapidly growing species, the variations of green moisture contents, bulk density, wood fibre dimensions, microfibril angles, and number of leaf knot in stem wood were investigated. The heartwood contained a higher moisture content than the corresponding sapwood. Bulk density in radial patterns variations decrease outward from the pith, then increase toward the bark. The wood-fiber length and diameters had somewhat smaller values than on Populus alba $\times$ glandulosa or Populus euramericana. The microfibril angles decreased rapidly toward the outside, and their mean values were about 16 degree. The grain angles run nearly parallel to the cell axies. Number of leaf knot showed a fluctural change above ground level to a point near the base of the crown and then increased rapidly to the top of tree and average number of leaf knot varied exclusively from tree to tree.