Studies on Variability in Wood Properties in Tree Stems of Pinus koraiensis (I) -Differences in Green Moisture Content and Shrinkage between Heartwood and Sapwood-

잣나무 수간내 재질변동에 관한 연구(I) -심재와 변재의 생재함수율과 수축율 차이-

Korean pine(Pinus koraiensis S. et Z.) is an economically important species in Korea because it will be harvested largely within next 20~30 years. The purpose of this study was to investigate changes in green moisture content, specific gravity and shrinkage in the stems of a Korean pine trees to provide fundamental information for technical processes. The followings are the results of this study. 1. There were about 110% differences in the heartwood and sapwood' green moisture contents (heartwood=59.5%; sapwood=170.6%). 2. There were no significant differences in average volumetric shrinkage between heratwood and sapwood, even though there were significant differences in moisture contents between them. Therefore, moisture content did not significantly influence on the shrinkage. 3. There was no significant relationship between height and shrinkage in heartwood. However, in the sapwood, shrinkage was highly correlated with the height. 4. Shrinkage levels were the most significant in south-bound direction and least significant in north-bound direction in both heartwood and sapwood. 5. There was a positive correlation between specific gravity and shrinkage in the sapwood. However, no such a relationship was found in the heartwood.