测定立木材积的改进形点法

为了测定立木的材积，该文应用孔兹干曲线方程建立了表达整株树干形状的连续干曲线方程组和树干材积的精准区分求积式.据此，推导出立木的改进形点法求积式.为了克服对形点的观测困难，该文又提出了形点高的推定式，便于发挥外业调查的工作效率.以精准区分求积式所求材积为真值，中央断面区分求积法、改进前的立木形点法和改进形点法分别与其进行比较，理论与实验证明，改进形点法测定立木材积的过程简便易行，具有更高的准确度、通用性和实用性. 

Precision form method to determine standing wood volume.

In order to survey standing wood volume, based on Kunze Trunk Curve Equation, the authors built another continuous trunk curve equation set to describe whole trunk form. At the same time, precision volume calculation equation by section was put forward. An improved tree accurate volume measurement equation of form point method had been thus deduced. They also worked out an upward deduction equation in form point height h-2 to conquer difficulties in surveying form points,and increase the efficiency of forestry investigation. Therory and experiment have proved that under the precondition of setting the trunk volume surveyed by precision volume calculation equation by section as true number, compared with mid-area sectional measurement method of the volume and the old form point method, improved form point method is simple and operative, more accurate and practicable.