北京东灵山地区金龟群落物种组成及多样性变化

Species composition and diversity of scarab beetle (Coleoptera: Scarabaeoidea) communities at Dongling Mountain,Beijing

本文研究了北京西部东灵山地区金龟群落的物种组成和多样性变化。选择 11种不同的生境类型 ,分别代表该地区的植被类型与环境变化 ;野外取样重复 3年 (1998～ 2 0 0 0年 ) ,共获得金龟标本 172 1号 ,其中 ,腐食性金龟有6属 2 0种 ,占总数的 89.2 % ,植食性金龟有 2 0属 2 6种 ,占总数的 10 .8%。分别按样地内腐食性和植食性金龟的种类和数量对生境进行主成分分析排序 ,以及按样地内物种种类对生境进行系统聚类分析 ,两者的计算结果基本一致 ,可以将东灵山地区的生境类型划分为 3组 :即梨园岭退耕区的灌丛植被、小龙门林区的森林植被和东灵山主峰区的亚高山植被 ,梨园岭退耕区的辽东栎 (Quercusliaotungensis)萌生丛被合并到小龙门林区森林植被类型中 ,反映了海拔高度和植被类型可能是决定该地区金龟群落组成和分布的主要因素。对这 3组生境类型内的金龟群落进行物种多样性分析 :腐食性和植食性金龟的个体数量、物种丰富度 (S)及多样性指数 (H′)的变化趋势相似 ,均以灌丛植被内较高 ,而在亚高山植被内较低。腐食性金龟的均匀度指数 (J)在森林植被内较高 ,在亚高山植被内较低 ;而植食性金龟的均匀度指数在亚高山植被内较高 ,灌丛内较低。比较常见种的生境选择 ,并进行种间的相关分析 ,可以看出

We investigated the species composition and distribution of the scarab beetle (Coleoptera: Scarabaeoidea) community in Dongling Mountain (39°48′～40°02′ N, 115°24′～115°36′ E), 114 km to the west of Beijing. Three sites containing 11 plots were selected to reflect the effect of vegetation, elevation and human disturbance on scarab beetle communities. During the growing seasons of 1998 to 2000, a total of 1721 scarab beetles were captured. Six genera and 20 species of saprophages and 20 genera and 26 species of phytophages accounted for 89.2% and 10.8% of total beetle specimens, respectively. Principal component analysis (PCA) and cluster analysis were used to analyze the phytophagous and saprophagous scarab species. Similar results were obtained: the 11 plots were grouped into three categories: the shrubs at low elevation (Liyuanling), forests at low elevation (forests in Xiaolongmen and coppices Liyuanling), and alpine vegetation (the top of Dongling Mountain). This indicates that vegetation and elevation may be important factors that influence the distribution of scarab beetles in Dongling Mountain. Species diversity ( H′ ), species richness ( S ) and number of individuals were computed for the three categories: all were highest in shrubs and the lowest in alpine vegetation. Species evenness ( J ) of the three categories showed a complicated patterns of variation: for the saprophagous assemblage, the highest value was observed in forests and the lowest one in alpine vegetation; for the phytophagous assemblage, the highest value was in alpine vegetation and the lowest was in shrubs. The co occurrence between common species was analyzed. For saprophagous species, Caccobius sibiricus was positively correlated to Liatongus phanaeoides and Onthophagus sp1., but all of them were negatively correlated to Onthophagus sinicus. For phytophagous species, Serica orientalis and Brahmina faldermanni showed a significantly positive correlation, and Trichoserica heydeni, Trichoserica heydeni and Clinterocera mandarina were another positively correlated group. Positive or negative correlations between these species were consistent with their abundance in the different habitats and reflect similarities and differences in their habitat preferences.