摘要：以翔实的数据论述了黑龙江森工林区当前所出现的“两危”是由于历经半个世纪的过量采伐,使森林一系列内在结构失调所致。提出治危兴林、施行森林分类经营的主要任务,提出了土地利用结构、林种结构、森林经营周期结构、森林起源结构、优势林分结构、宏观的林分组成树种结构、林分龄组结构、林分密度结构、径阶结构的调整指标和调整对策。

摘要：In order to realize the effect of second generation of larch plantations on soil fertility and tree growth and to provide the theoretical base and the reasonable management measures, the growth of larch plantations for different generations at different soil conditions were inventoried and compared. The relationship between soil nutrition and tree growth of the second-generation larch plantations was analyzed. Comparing with the first generation, the second generation of larch did not present acidation phenomenon on the dark brown soil. With respect to the organic matter, rapidly available K and N, the values of the second-generation larch is close to that of first generation at later time. Platform-preparation is good measures for improving soil conditions