山西华北落叶松林分类学多样性

Taxonomic diversity of Larix principis-rupprechtii forests in Shanxi Province

以山西华北落叶松林为研究对象,调查了40个样地,共记录了219种植物,隶属于3门5纲34目49科145属。山西华北落叶松林下的物种组成和分类单元比较丰富,但主要以几个大的分类单元为主;在目的水平上集中于蔷薇目和桔梗目,在科水平上集中于菊科、蔷薇科、毛茛科。植物科内种、属组成差异较大。应用平均分类差异指数Δ+与分类差异变异指数Λ+对山西华北落叶松群落进行了分类学多样性分析,结果表明:40个样地的Δ+值大部分位于理论平均值曲线之上,说明山西华北落叶松林物种分类多样性较大,物种间的亲缘关系较远;所有样地的Λ+值均位于Λ+值的理论平均值曲线之上,表明山西华北落叶松林物种分类等级的均匀度较差,低于平均理论均匀度。平均分类差异指数Δ+与环境因子中的经度、坡度、坡位、海拔和种数相关性显著(P<0.05),与纬度和坡向相关性不显著(P>0.05);分类差异变异指数Λ+与海拔、经度、坡度和种数相关性显著(P<0.05),与纬度、坡向和坡位相关性不显著。

To explore the taxonomic diversity of Larix principis-rupprechtii forests in Shanxi, 40 stands were investigated. In total 219 species were recorded, belonging to 145 genera, 49 fami- lies, 34 orders, 5 classes, and 3 phyla. In spite of the great species richness, most species fell within a small number of taxa. The dominant orders were Rosales and Campanulales, and the dominant families Compositae, Rosaceae, and Ranunculaceae, and the compositions of genera and species within families exhibited differences. The average taxonomic difference index （Δ^＋） and the taxonomic difference variation index （Λ^＋） were used to measure the taxonomic diversity of L. principis-rupprechtii forests. The results showed that most of the Δ^＋ values and all the Λ^＋ va- lues in the 40 stands were above their theoretical average values, respectively, which suggested that the species in the forests had high taxonomic diversity and were mainly composed of distant relatives, while there was a low evenness in taxonomic hierarchies. The Δ^＋ value was significantly correlated with the environmental factors （P〈0.05） , such as longitude, slope, slope position, altitude and species number, but the correlation between Δ^＋ and latitude and aspect was not sig- nificant （P〉0.05）. Moreover, the Λ^＋ value had a significant correlation with altitude, longitude, slope and species number （P〈0.05）, while it had no significant correlation with latitude, aspect and slope position （P〉0.05）.