Interspecific Association and Niche Characteristics of Taxus chinensis var. mairei Communities in Lingchuan, Shanxi

Based on sample investigations of Taxus chinensis (Pilger) Rehd. var. mairei (Lemee et Levl.) Cheng et L.K. Fu communities in Lingchuan County, Shanxi Province, interspecific correlation and niche characteristics were studied by overall correlation test VR, Pearson correlation index, Spearman rank correlation index, and Niche measurement. Results showed that:(1) Taxus chinensis (Pilger) Rehd. var. mairei (Lemee et Levl.) Cheng et L.K. Fu, Vitex negundo L. var. heterophylla (Franch.) Rehd., Carpinus turczaninowii Hance, Forsythia suspensa (Thunb.) Vahl, and Spiraea trilobata L. were constructive or dominant species, and had higher importance values and broader niche breadths in the community; (2) Higher niche overlap between species meant stronger interspecific competition, especially between Taxus chinensis var. mairei and others; (3) Whole associations in the community showed significantly negative correlations, and most species pairs were neutrally associated; (4) Both Pearson and Spearman rank correlation indices showed significantly positive correlations with niche overlap. However, there was no direct linear correlation between niche overlap and breadth. In other words, interspecific competition was strengthened with increasing interspecific correlation, but was not directly related to niche breadth. This study provides reasonable and theoretical support for the protection and utilization of natural resources of Taxus chinensis (Pilger) Rehd. var. mairei (Lemee et Levl.) Cheng et L.K. Fu in this region.