羊草草原植被不同演替阶段土壤鞘翅目昆虫群落特征

CHARACTERISTICS OF COLEOPTERAN COMMUNITIES IN SOILS UNDER DIFFERENT STAGES OF VEGETATION SUCCESSION OF LEYMUS CHINENSISGRASSLAND

2007年6月、8月、10月对吉林省羊草草原植被不同演替阶段的土壤鞘翅目昆虫进行调查,共获取土壤鞘翅目昆虫19科,1 670只,优势类群3类:步甲科、隐翅甲科、象甲科幼虫,其中象甲科幼虫为广布类群。不同演替植被生境中土壤鞘翅目昆虫在类群及数量组成上存在明显差异,其垂直分布具有明显的表聚性。土壤鞘翅目昆虫群落多样性指数(H′)表现为:羊草群落>羊草+虎尾草群落>虎尾草群落>碱蓬群落,这与植被演替进程密切相关。不同演替阶段植物群落中土壤鞘翅目昆虫个体数、类群数及多样性指数(H′)均存在明显的季节变化,除虎尾草群落外,个体数在8月份达到最大值。灰色关联分析结果表明土壤鞘翅目昆虫受土壤含水量、pH、土壤有机质等土壤环境因子的影响明显。

Characteristics of coleopterans in soil at different stages of vegetation succession of Leymus chinensis grassland were studied in Jilin Province in June, August and October of 2007. A total of 1 670 soil coleopteran in- dividuals were captured and fell into 19 families, among which Carabidae, Staphylinidae, Curculionidae larvae were dominant, and especially the latter were found almost everywhere. Significant differences were found in num- ber of individuals and groups of soil coleopterans between the stages. The vertical distribution of soil coleopterans was characterized by gathering in the surface soil. Diversity index（H＇） of the soil coleopterans varied from stage to stage, showing an order of Leymus chinensis community 〉 Leyrnus chinensis ＋ Chloris virgata community 〉 Chloris virgata community 〉 Suaeda salsa community, which was closely related to the process of vegetation succession. Seasonal changes were quite obvious in individual number, group number and diversity index（H＇） of the soil coleopterans and the number of individuals peaked in August, except for the stage of Chloris virgata community. Grey correlation analysis revealed that soil water content, soil pH and soil organic matter are factors significantly affecting soil coleopterans.