The Timber Properties of Birch Grown in a Plantation in Atsuma, Hokkaido

The wood qualities of birch species grown in a plantation in Atsuma, Hokkaido, were investigated. Shirakamba (Japanese white birch ; Betula platyphylla), Udaikamba (Japanese red birch ; Betula maximowicziana) and Dakekamba(Erman’s birch ; Betula ermanii) were used. Disks were cut from the trunk at part of 2 m height above the ground and the ring widths were measured. Bending tests and compression tests were carried out. The initial radial growth of Dakekamba was smaller than that of the other species. Wood density decreased from bark to pith. The closer to the pith, the lower the bending and compression strengths were. There was little change in density or the bending and compression strengths at ground height. The plantation grown birches showed similar strength performance as naturally grown birches.