As high expectation is placed on natural Japanese White Birch forests in the Yinshan Mountains to serve as public utility forests starting from the year 2010 when the current prohibition on logging will be lifted, the research on new thinning techniques is one of the most important challenges for the future. Drawing examples from the case of the State-owned Forest Farm of the Manhan Mountain, one of the Farms located in the Yinshan Mountains, during 1960-1997 before the prohibition of logging was inactive, this article attempts to examine and analyze the Farm management of that time as well as the thinning techniques used in the Japanese White Birch forests, and to identify the problems from managerial and technical perspectives.As a result, it become clear that, during the two periods - one under the "integrated accounting" management system and the other under the "transient" management system - when the Chinese government budgeted the cost required for the management of the Farm, the Farm managers were able to carry out their activities in a stable manner. However, during the period under the "autonomous" management system, the Farm became corporations with a self-supporting accounting system and the Farm managers had to run their organizations in an unstable condition as the Farm employee's salaries increased. Therefore, the stands requiring the thinning were put aside since thinning these stands was considered disadvantageous from a business point of view and therefore these are not profi table. In addition to this, population outfl ow which began in 1985 continued due to the introduction of the agricultural land contract system, especially among young people from the Manhan Mountain region, and thus the region suff ered a labor shortage during the thinning season from 1991 to 1997. Regarding thinning techniques, the low thinning based on the five-grade tree classifi cation could neither improve the characters of the remaining upper-story trees nor fully encourage their growth in thickness. As a consequence, the health of the stands and the future utilization rate of timber were not suffi ciently improved after the thinning was performed.
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