Study of the Site Class Index Chart of Larch Plantation Based on the Mitscherlich Model1

In this paper, 196 plots and 460 larches were selected as the material, and analyzed the oriented exponential order site class index curve model of larches located at Wangyedian in Chifeng City, Inner Mongolia. The forestal statistical analysis software (SPSS 18.0) was used to data fitting and analytic comparison of larch plantation data. The results showed that: the oriented Mitstcherlich curvilinear function was the more appropriate model of oriented larch plantation site class index curve after comprehensive considering of fitting accuracy, curve trend, distribution trend of sampling points and residual distribution. Based on regressive Mitstcherlich model, the paper selected 30a larches planted and operating level confirmed the exponential distance is 2m with 12 exponential orders, and then drew the site class curve cluster. Furthermore, the 12 exponential orders site class index table of larches located in Wangyedian, Chifeng City, Inner Mongolia was worked out.