闽北主要用材树种胸径与去皮地径关系的研究

本文利用闽北四县市收集的杉木９９４株、马尾松１０８７株、阔叶树１０３２株样木资料，按树种随机抽取１００组胸径与去皮地径的成对值，用５种胸径与去皮地径的回归方程对各树种进行拟合与检验．以剩余平方和最小者为优，比较得出：杉木、阔叶树以一元线性而马尾松以幂函数方程为佳，其相关系数分别为０．９９８５、０．９９５２、０．９８６５。用５０株模外样木资料对估测模型进行Ｆ检验和Ｕ检验，估测模型的系统误差和约方误均小于５％，表明模型预测精度较高，可供林业生产经营管理使用．

Study on Relations between Diameter at Breast Height and Diameter inside Bark at Ground for Main Timber Species in Northern Fujian

Among a vast of samples, including 994 trees of Chinese fir (Cunninghamia lanceolata), 1087trees of masson pine (Pinus massoniana)and 1032 trees of broad-leaved species, which obtained from four counties in northern Fujian,100 samples were selected ramdonly for each species to reveal the relations between diameter at breast height and diameter inside bark at ground by means of regressive equations. The mimic and test results with computer showed that one-element linear regressive equation was optimal to Chinese fir and broad-leaved species, their related coefficients were 0. 9985 0. 9952 respectively, and the optium regressive equation for masson pine was power function, its related coefficient was 0. 9965. F-test and U-test based on the data from 50 samples in yield proved the validation of these models for their system error and even error were all less than five percent. Therefor, it was useful for these modals in forest management.