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运用Ｎｅｌｄｅｒ密度试验设计方法，研究了大叶相思林分的树冠生长以及多干现象与密度的关系。结果表明：１年生时各种密度林分均未郁闭，３年生、５年生、７年生时郁闭林分的单株面积上限分别为３．１５ ｍ ２·株－ １、６．２０ ｍ ２·株－ １、７．００ ｍ ２·株－ １。５年生以后，树冠趋于稳定，１～３年生时树冠生长最大的单株面积为５．６４～６．８８ ｍ ２·株－ １，５～７年生时树冠最大的单株面积为１５．５０～１８．６８ ｍ ２·株－ １。林分平均树干数与密度则呈现幂函数关系，林分单株面积小于１ ｍ ２·株－ １时，多干木比例在１０％ 以下；林分密度超过１２．５３ ｍ ２·株－ １以后，多干木比例为１００％ 。
Using Nelder density test design method, the crown growth of Acacia macrostachya stands and the relationship between multi-dry phenomenon and density were studied. The results showed that no species of canopy density was closed at 1-year-old, and the upper limit of single-plant area of 3-year-old, 5-year-old and 7-year-old stands was 3.15 m 2 · plant -1.6.20 m 2 · Strain - 1, 7.00 m 2 · Strain - After 1.5 years of age, the crown of the tree tended to be stable. The area of the plant with the highest crown growth at 1 to 3 years was 5.64 to 6.88 m 2 · plant- The largest single canopy area from 1 year to 5 years to 7 years was 15.50-18.68 m 2 · plant -1. The average number of trunk and density of forest stands a power function relationship. When stand area per plant is less than 1 m 2 · plant - 1, the proportion of multiple dry wood is below 10%; the stand density exceeds 12.53 m 2 · plant - 1 Later, the proportion of more dry wood was 100%.