论文部分内容阅读
在编制林分密度控制图时，常用二次回归法求解模型Ｍ＝ＡｎＨＢ１１－Ａ１２ＪＢ１２Ｎ２和１／Ｄ＝Ａ２１ＨＢ２１＋Ａ２２ＨＢ２２Ｎ配制等树高线和等直径线，并以此为基础编制林分密度控制图，由于要经两次回归，加上其误差的迭加，所以其实际精度并不高，而利用非线性回归法则少一次求解各种模型。在编制太行山区油松人工林密度控制图中采用非线性回归法求解模型Ｍ＝Ａ１１ＨＢ１１Ｎ－Ａ１２ＨＢ１２Ｎ２配等树高线，精度达９７．３３％，提高了５．８３％，求解模型Ｍ＝Ａ２１ＤＢ２１ＮＡ１１ＤＢ２２配制等直径线，精度达９８．６％，从而使新编的林分密度控制图精度大大提高。
In the preparation of stand density control plots, commonly used quadratic regression method to solve the model M = AnHB11-A12JB12N2 and 1 / D = A21HB21 + A22HB22N preparation such as tree height and diameter lines, and based on the preparation of stand density control chart, due to To go through two regression, plus the superposition of its error, so the actual accuracy is not high, but the use of non-linear regression method to solve the various models less once. In the preparation of the plantation density control chart of Pinus tabulaeformis in Taihang Mountain, nonlinear regression method was used to solve the tree height line of model M = A11HB11N-A12HB12N2 with the precision of 97.33% and the increase of 5.83%. The solution model M = A21DB21NA11DB22 Such as diameter, the accuracy of 98.6%, so that the newly compiled stand density control chart greatly improve the accuracy.