一般认为,景观斑块面积和破碎化对物种丰富度有重要的影响。在宁夏中部荒漠地区,天然柠条林和人工柠条林地交错排列,形成点、片、带状等大小不等的斑块性分布,表现为典型的破碎化斑块格局生境特征。本文采用巴氏罐诱法调查了在小尺度下荒漠景观人工柠条林破碎化生境不同斑块内地表甲虫的物种多样性。结果共获得9科20属29种地表甲虫。拟步甲科昆虫占绝对优势,阿小鳖甲、克小鳖甲为优势种。Rarefaction曲线显示较大的斑块面积有较多的物种多样性,但群落多样性指数各斑块差异不显著。利用斑块面积对物种数-个体数进行回归分析表明,地表甲虫的物种多样性受斑块面积的影响,生境的破碎化会导致地表甲虫多样性下降。
There is increasing empirical evidence that the habitat area and fragmentation play an important role in determining species diversity and distribution patterns. Due to poor conditions, topography uneven distribution and other factors involved, the Caragana scrubland in arid zone of central Ningxia showed a pattern of dot, patch and strip separated by natural and cultivated forest which forms typical fragmented landscapes. To evaluate the fragmentation effected to biodiversity in fine scale of Caragana shrubbery landscape, we studied ground-dwelling beetles diversity using pitfall traps method. A total of 336 individuals representing 29 species and 28 genera of ground-dwelling beetles were captured. The dominant family was Tenebrionidae. Microdera kraatzi kraatz and Microdera kraatzi alashanica were the dominant species. Rarefaction curve showed that the larger patch area had more species diversity. However, the diversity index of each patch was no significant difference. Using patch area on species and the number of individuals, regression analysis showed that the diversity of ground-dwelling beetles was affected by the influence of patch area. Habitat fragmentation decreased the diversity of ground-dwelling beetles.