低产林分改造,是发挥林业潜在生产力,开展森林永续利用的一个重要方面,也是森林管理的一项基本内容.目前,杉木低产林分改造,在镇江低山丘陵区已成为林业发展的当务之急.为此,镇江地区林学会组织了低产林成因、改造途径和经济效益的专题考察.通过全面深入考察,初步研究得出“四四”结论,即:确定了杉木低产林的四条标准,明确了杉木低产林形成的四个主要原因,提出了杉木低产林改造的四点规划意见和四条基本措施.现将考察材料整理于下,供各地杉木低产林改造时参考. The transformation of low-yielding stands is an important aspect of developing forestry potential productivity and sustainable use of forests, and is also an essential part of forest management. At present, the transformation of low-yielding Chinese fir stands has become a top priority in forestry development in the hilly area of ​​Zhenjiang .Therefore, the Zhenjiang Institute of Forestry organized the thematic study on the causes, transformation ways and economic benefits of low-yield forests.From the thorough and thorough investigation, the conclusion of “April 4” was obtained through preliminary study, that is, the four criteria of low-yield forests of Cunninghamia lanceolata Four main reasons for the formation of Chinese fir low-yield forest were proposed, and the four points of planning and four basic measures for the transformation of Chinese fir low-yield forest were put forward.