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我们在测定林分平均直径时采用一种按数理统计诱导出来的方法。首先计算分析了秦岭林区147块标准地优势林分直径的平均变异系数,然后按数理统计中 n=(W~2/P~2)公式(n—抽样株数,W—变异系数,P—精度指标)计算出要求不同精度时测定平均直径需要抽样的最少株数。其结果:平均变异系数为 W=
We used a mathematical-based method to derive the mean diameter of the forest. The average coefficient of variation (CV) of dominant stand diameter of 147 standard plots in Qinling forest area was calculated and analyzed. According to the mathematical formula of n = (W ~ 2 / P ~ 2) Accuracy Index) Calculate the minimum number of strands that need sampling for determining the average diameter when different precision is required. The result: the average coefficient of variation W =