预估间伐后林分直径分布特征数的研究

在Ｍｕｒｒａｙ方法的基础上，提出更一般的间伐分离参数，推导保留木和间伐木直径分布Ｋ阶矩的预估方程，并用贵州马尾松人工林间伐试验材料对方程的适应性进行验证。同林预估结果表明，方程的理论值与实测值之间只存在微小的舍入误差，方程为确定性方程；异林预估结果表明，总体上，保留木的预估效果比间伐木的好，原点矩的预估精度比中心矩的高；该方法除具有与Ｍｕｒｒａｙ方法同样的作用和效果外，还能预估诸如林分断面积平均直径、偏度等所需要的多阶矩。在中、强度间伐的经营条件下，如何有效地预估林分直径分布的形状特征数，是有待解决的问题。

The Study on Prediction Characteristic Number of the Diameter Distribution After Thinning

On the basis of Murray method,this paper introduces more general thinning sepa-ration parameters and derives equations predicting k-power moments of the remaining and thethinned distributions. Some tests were made to see if the equation.q are reasonable and the pre-dicting results are identical with practical data of Masson pine plantations in Guizhou. The out-comes make it clear that the theoretical values of the functions tally with the practical values. Ingeneral,the prediction result of the rernaining trees is better than that of the thinned trees, andthe prediction precision of the origin moments is higher than that of the central moments.More-over,the method of this paper can predict multi-power moments(for example,ones concernedwith average basal area,skewnessand so on)in addition to having the same use and effectivnesswith Murray method.Certainly,it will need to be solved further about how to predict the shapefeature of the diameter distributions with large cutting proportion.