【摘要】 在指出了森林林分材积计算的标准本方法偏低估计实际材积的系统误差的基础上，提出了两种校正方案。校正系数可以从在林分内选择标准木的采样样本的数据中方便地算出。模拟举例计算说明两种校正方案基本消除了原公式的系统偏差。校正后的公式为：其中：为林分材积估计值；ＶＢＫ和ＡＢＫ分别是第Ｋ株标准木的测量材积和胸高断面面积；ＡＴ是林分的总胸高断面面积：ｈＢ，和ｄＢ是抽样算得的具有平均胸高断面面积的树的高度和胸径；ｄＷ是抽样算得的以胸高断面面积为权重的加权平均胸径；ｂ是树高曲线在ｄ＝ｄＢ处的斜率。校正的第２方案具有与上式完全相同的形式，只是标准木的是具有平均胸径的树木。更多还原

【Abstract】 The systematic underestimation error of forest timber by using standard sample trees was pointed out. And 2 correction methods were proposed with easy estimation of the correction factors from the sampling data. The traditional formula is In contrast. the corrected formula iswhere VTE and are the estimated timber volume for whole quadrat using the original formula and the corrected formula respectively. VBK and ABK are respectively the measured timber volume and breast height cross-sectional area of K’th standard sample tree. AT is the total breast height cross-sectional area in the quadrat; hB and dB are respectively the height and breast diameter of the tree with average breast height cross-sectional areal dw is the average breast height diameter weighted by breast height cross-sectional area ; an db is the slope of the tree height curve at d=dB, dB, hB and dw can be es timated by sampling in the quadrat. b can be obtained either from given tree height curve or by applying linear regression to the same sample data for estimation of dB, hB and dw. The second correction of tEe formula has exactly the same form as the above equation, except tEe n standard sample trees are selected to have breast height diameters closest to the average breast height diameter in the quadrat. Thus dB and hB should be replaced by statistically estimated average breast height diameter and average tree height in the quadrat.更多还原