鄂尔多斯高原地区昆虫物种多样性研究

鄂尔多斯高原有特殊生境类型，本文研究了该地区的昆虫物种多样性变化及影响因素，得到以下结果：（1）利用巴氏罐诱法得到昆虫标本约5159号，其他无脊椎动物标本291号，鞘翅目为优势昆虫类群，其数量占昆虫标本总数的45．8％，其中拟步甲和步甲个体数量较多，占所有甲虫总数92．8％；（2）根据甲虫的物种多样性和丰富度的特点将4个调查地点分为两组：一组为以荒漠灌丛为主的杭锦旗和植被类型多样化的石灰庙，物种多样性指数，丰富度和个体数量较高；另一组为以人工植被区为主的石龙庙和新街镇，物种均匀度指数较高；（3）主成分排序（PCA）可以将该地区的甲虫群落分为人工植被区和荒漠植被区2种类型，反映降水和植被类型是决定甲虫群落组成的关键因素；（4）降水梯度对甲虫物种多样性有很大影响，物种多样性指数，均匀度指数与降水梯度呈显著的正相关关系；个体数量与降水梯度呈显著的负相关关系；物种的丰富度与降水梯度没有相关关系。以上结果表明，在鄂尔多斯高原地区，只有减少人为干扰，加强保护脆弱的原有植被，才能保护特有的昆虫种类；只有大力开展固沙造林植草，才能改善环境，提高该地区的昆虫物种多样性。

Species diversity of insects on the Ordos Plateau, Northwest China

This study investigates characteristics and patterns of insect species diversity on the Ordos Plateau, a special ecotone with extremely arid environments in Northwest China. Using pitfall traps, we collected 5159 insect specimen and 291 other invertebrates. As the most dominant group, beetles accounted for 45.8% of the total collected insects, and among beetles, 92.8% of individuals are Tenebrionidae and Carabidae. Plotting the log values of individual numbers of different beetle species, from high to low, results in patterns that separate the four investigated sites into two groups. One includes Hangjinqi, with mainly desert shrub environments, and Shihuimiao with a variety of habitats of different vegetation. The other includes Shilongmiao and Xinjiezhen with different environments, frequently artificial regeneration. The former exhibits high species diversity and richness, whereas the latter exhibits high evenness. Principal Component Analysis (PCA) ordination of beetle communities indicates that the species distribution was determined by precipitation gradient and vegetation types. A positive correlation is seen between precipitation and beetle species diversity and evenness, while a negative correlation is one exhibited between precipitation and individual numbers. Species richness does not show such patterns. Thus, in an arid region as the Ordos Plateau, special insect species and their natural communities can be preserved only when the original vegetation is well protected and the disturbances of human activity are effectively limited. The environments in this region can be improved and a high insect diversity can be developed when regeneration is increased and drift sanddune is decreased in most parts of this region.