庞泉沟自然保护区主要树种直径正态分布拟合研究

通过对庞泉沟自然保护区的华北落叶松、油松、山杨、白桦和辽东栎5种主要树种直径实测调查,利用χ2检验及曲线分布趋势来确定它们总体分布是否服从正态分布。对于服从正态分布的树种利用极大似然估计和最优同变估计对未知参数进行估计。分析和比较得知,最优同变估计对未知参数进行估计能使正态分布在林分直径分布拟合中更为精确。结果表明:华北落叶松、油松、山杨、白桦的直径服从正态分布,而辽东栎不服从正态分布。并对该区服从正态分布的树种直径总体进行了动态预测。

Research on the Fitting for the Normal Distribution of Main Tree species' Diameter in Pangquangou Nature Reserve

A practical investigation of the five main tree species’ diameter, Larix Principis-rupprechtii, Chinese Pine, Populus davidiana, Betula platyphylla, Quercus Liaotungensis, is conducted in Pangquangou Nature Reserve. The χ2 test and curve distribution trend are used to ascertain if they obey the normal distribution. To the tree species, the maximum likelihood estimation and minimum risk equivariant estimation are used to estimate the unknown parameters. The analysis and comparison of the above two methods show that the result of minimum risk equivariant estimation in fitting the stand forest diameters is more precise. The result indicates that the diameters of Larix Principis-rupprechtii, Chinese Pine, Populus davidiana, Betula platyphylla belong to the normal distribution, while that of Quercus Liaotungensis does not. And dynamic prediction of the diameters of the trees obeying normal distribution in this area is also done.