用树干表面积建立立木材积连年生长量模型的研究

本文采用相对区分法建立了12个伐倒木树干表面积区分求积式。采用0.1h相对区分,中央断面区分求表面积式、平均断面区分求表面积式与牛顿区分求表面积式的精度近似,系统误差(C％)与均方差(MSD％)近似于零。圆台区分求表面积式C％<±0.02％,MSD％<0.13％。公式的应用精度均较高。用树干表面积与平均直径生长量建立立木材积连年生长量模型Z_v=αSZ_v,模型的预测精度均较高。

Construction of Annual Volume Growth Model of Standing Tree by Means of Stem Surface Area Formula

Sectional measurement by means of stem surface area formula of 12 felled trees was founded from relative sectional measurements. Using 0.1h relation section, the precisions of sectional measurements by means of Huber's formula, or average cross section surface area formula and Newtons formula were all approximate. The systematic error (C%) and mean square deviatioa(MSD%) were approximate zero. Sectional measurement by means of cone frustum surface area formula C% was < 0.02%, and MSD% was<0. 13%. Application precision of these formulas were all high. Annual volume growth model of standing tree Zv = aSZd was constructed by using stem surface area and mean diameter growth. The predicting precision of the model is high.