通过对中条山混沟地区森林植被调查资料的多元分析——TWINSPAN分类、CCA排序与环境解释，划分了该地区的植被类型，给出了植被与环境因子的定量关系。结果如下 ：1）40个样地可划分为青檀林（Form. Pteroceltis tatarinowii）、栾树林（Form. Koelreuteria paniculata）、槲栎林（Form.Quercus aliena）、栓皮栎林（Form. Quercus variabilis）、鹅耳枥 + 葛萝槭林（Form. Carpinus turczaninowii + Acer grosseri）、元宝槭 + 千金榆林（Form. Acer truncatum + Carpinus cordata）和辽东栎林（Form. Quercus liaotungensis）7种群落类型，体现了中条山地带性植被类型为暖温带落叶阔叶林的特点。2）群落类型的划分主要反映了CCA排序第一、二轴的环境梯度，CCA排序第一轴突出反映了海拔与土壤养分梯度，第二轴与土壤pH值、湿度指数和坡度显著相关。总体来说，海拔和土壤因子是影响混沟地区乔木物种分布分异的最主要环境因子。3）环境因子和空间因子解释了物种格局变化的46.14%，其中环境因子占30.79%，空间因子占8.48%，空间因子 和环境因子交互作用解释的部分占6.87%。良好的环境解释反映了调查取样和环境因子选取的合理性，同时也体现了混沟地区植被的原始性。
The forest vegetation was investigated through 40 carefully designed sampling plots in Hungou, Zhongtiao Mountain. Within each plot, the main environmental factors, such as altitude, slope, aspect and soil depth, were measured using portable GPS instruments and field tools. Soil samples also were collected and analyzed in the laboratory for total N, organic matter content, and pH. Topographic relative moisture index (TRMI) and annual total solar radiation were calculated using a Digital Elevation Model (DEM) (scale 1:50 000). Community types were classified using TWINSPAN and the relationship between the distribution and a bundance of species to environmental gradients was analyzed using CCA ordination . The 40 plots were divided into 7 plant formations: Pteroceltis tatarinowii, Koelreuteria paniculata, Quercus aliena, Quercus variabilis, Carpinus turczanin owii + Acer grosseri, Acer truncatum + Carpinus cordata, and Quercus liaotungensis. The floristic composition of the arboreal species in each community represented the characteristics of the different deciduous broad－leaved forests in the warm temperate zone of North China. The distribution pattern of the community types classified by TWINSPAN was coincident with the environmental gradients shown in the diagram of the first two CCA axes. The first CCA axis mainly expressed altitude and soil fertility, and the second axis had distinct relationships with soil pH, TRMI, and slope gradient. These results, in general, indicate that the spatial distribution of tree species in Hungou is mainly controlled by altitude, soil fertility, and biotope humidity, whereas soil depth, annual global radiation and slope aspect are secondary controls. Environmental and spatial variation accounted for 46.14% of the spatial distribution of tree species, of which environmental variation alone explained 30.79%, spatial variation was 8.48%, and the interaction of spatial and environmental variation was 6.87% of the variation. These results indicate that we measured the important environmental factors regulating species distribution patterns in this forest.