一种与直径分布型无关的预测林分直径累积分布的方法

本文推导出一组联系林分平均直径生长和直径累积分布生长之间的方程式。根据这些方程建立的全林分生长模型和径阶模型或与距离无关的单木模型之间的关系，可以指导由林分断面积总生长向单木直径生长的分配。采用这一组方程，根据二个不同时间点上算术平均直径和均方平均直径回收生长模型和枯损模型中的参数，保证林分水平预测的结果和径级水平或单木水平预测的结果相容。采用一个误差函数来刻化相同直径林木在生长过程中的分化，证明了忽略这项误差函数可能导致预测的直径分布范围小于实际的范围。因此，加上一个误差函数预测直径分布在一定程度上提高了直径分布预测的精度。最后一个实例说明计算过程。

A DISTRIBUTION FREE METHOD TO ESTIMATE STAND DIAMETER CUMULATIVE DISTRIBUTION

A group of equations relating stand mean attributes to stand diameter cumulative distribution has been developed which can be used to build relations among whole stand model, size class model, and distance - independent individual tree model. These equations can be used to allocate stand gross basal area growth to each individual tree. Parameters in diameter growth and mortality models can be recovered using these equations and based on arithmetic mean diameter and quadratic mean diarneter, therefore the compatibility between estimations from stand model , size class model , and individual tree model are guaranteed. An error function in the group is used to .describe diffrentiation process of trees with the same diameter at initial stage and it has been proved that estimated diameter range will be smaller than the real one if such An error function is ingnored. Introducing this error function into the models improves the models' accuracy in predicting diameter distribution. An example is giv- en to show the models' applicability .