杨树工业用材林材种蓄积量测定方法研究

从拟合的四类回归模型系列中，选定其中相关比（系数）最大，标准差最小的二元二次六项式曲面回归方程式８个，二元线性回归方程式１个。用以测算杨树立木小头直径６～３０ｃｍ的各类材种材积和材种蓄积量，其系统误差不超过５％。用林分平均胸径和平均树高值直接代入相应方程式，可取得与每木（或分组）代入方法相同精度的材种蓄积量的计算结果。

A Study on the Testing Method of Growing Stock of Timber Assortments of Poplar Industrial Forest

Abstract in this paper,four sorts of models were used,and from them nine regression epuations which havethe biggest coefficient of regression and the smallest standard deviation were selected out. According to theseequations,the growing stocks of timber assortments whose diameter at small end were from 6cm to 30cmwere calculated,the systematic error were less than 5%. It can reach the same accuracy with calcuhting byaverage stand's height and breast height diameter as by individual or grouping valines.Subiect words Poplar, Industrial timber forest, Growing stock of timber assortments, regression equation,Testing method