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采取克拉夫特分级法d=r/的公式(r:林木胸径,R:林分平均胸径),进行Ⅰ-Ⅴ级木分类,以大青山油松人工林、落叶松人工林和白桦天然次生林为主要研究对象,对比分析不同密度下林木分级、竞争和径阶的变化情况,为大青山植树造林提供相对适宜的密度区间。结果表明:大青山油松人工林密度不宜超过3200株/hm2,落叶松在1700株/hm2时林木分化现象并不明显。白桦天然次生林因萌生起源、年龄因素的影响,密度对其分级木影响效应不显著。
According to the formula of Kraft classification d = r / (r: DBH, R: average DBH of the stands), Ⅰ-Ⅴ grade woods were classified. The Pinus tabulaeformis plantation, Larix gmelinii plantation and Betula platyphylla The secondary forest was the main research object. The changes of the grading, competition and diameter of the trees under different densities were compared and analyzed to provide relative suitable densities for Daqingshan afforestation. The results showed that the density of Pinus tabulaeformis plantation in Daqingshan Mountain should not exceed 3200 plants / hm2, and the larch differentiation was not obvious when the larch was at 1700 plants / hm2. The natural secondary forest of Betula platyphylla was not affected by the origin of germination and the influence of age.