近年来,日本战后栽植的林地已逐渐进入间伐期,必须进作间伐的林地面积正在急剧增加。但是,传统的下层间伐法,因其间伐材多为用途不大的小径材或有各种缺陷的劣质材,经济性差,很不实用。为此,日本林业试验场四国分场从1971年至1982年进行了间伐对比试验。 In recent years, the woodlands planted by Japan after the war have gradually entered the thinning period and the area of ​​forest land that must be moved to thinning is rapidly increasing. However, the traditional lower thinning method is not practical due to its poor economic efficiency due to the fact that thinning materials are mostly small-diameter materials or poor quality materials with various defects. To this end, the Japanese forestry pilot field four branch from 1971 to 1982 conducted a comparative thinning comparison test.