在毛主席“绿化祖国”、“实行大地园林化”的伟大号召下,小兴安岭伊春林区营造了大面积落叶松人工林。目前,林龄超过20年的人工林已开始进行第一次间伐,生产上迫切要求合理确定间伐起始年限。为此,我们研究了 Under the great call of Chairman Mao’s “greening the motherland,” and implementing “the practice of the earth garden,” the large-area larch plantation was built in the Yichun forest area in Xiaoxing’anling. At present, the planted forests of more than 20 years of age have begun the first round of thinning and the production is urgently required to determine the starting period of thinning reasonably. To this end, we studied