The Research Of Community Characteristics And Ecological Distribution Of Soil Coleopteran In The Leymus Chinensis Grassland Of Jilin Province

The sampling sites chosen for this study included five plant communities of leymus chinensis grassland of Jilin province in the region of Changling,namely Leymus chinensis community, Leymus chinensis + Chloris virgata community, Chloris virgata community, Puccinellia tenuiflora community, Suaeda salsa community. We investigated community Characteristics and Ecological distribution of soil coleopteran in different plant communities of leymus chinensis grassland during the period of May to October in 2007.A total of 2863 soil coleopteran individuals was captured and fell into 29 families in five different plant commuities of leymus chinensis grassland,which included 1558 soil coleopteran larvaes and belonged to 17 families,1305 soil coleopteran adults and belonged to 21 families. Curculionidae larvae, Carabidae,Staphylinidae were the dominant groups and accounted for 74.71% of the total captured.The horizontal distribution of soi coleopterans in different plant communities of leymus chinensis grassland showed that: as to the group number, Leymus chinensis + Chloris virgata community> Leymus chinensis community> Suaeda salsa community> Puccinellia tenuiflora community= Chloris virgata community;As for the individual number, Leymus chinensis community> Suaeda salsa community> Puccinellia tenuiflora community> Leymus chinensis + Chloris virgata community> Chloris virgata community.The trend of dynamic change of different plant communities'individual number and group number was nearly consistent.Both individual number and group number arrivaled at peak in August, but as for the least number they were different.The community diversity of soi coleopterans showed that : as for H′index and E index, Leymus chinensis + Chloris virgata community> Leymus chinensis community> Chloris virgata community> Suaeda salsa community> Puccinellia tenuiflora community,and the change trend of C index was reverse with J index. The trend of dynamic change of different plant communities was different. The similar index of soi coleopteran community among different plant communities changed in different months,and the similar indexs of Leymus chinensis + Chloris virgata community and Leymus chinensis community, Suaeda salsa community and Puccinellia tenuiflora community were more higher.The individual number and group number of soi coleopterans in different plant communities of leymus chinensis grassland decreased with the increasing of the depth of soil layer,but it was not the entirely same. The change scope of individual number was larger than the group number's. As for the vertical distribution of individual number of soi coleopterans in leymus chinensis grassland, Leymus chinensis community, Leymus chinensis + Chloris virgata community and Suaeda salsa community put up obvious nature of surface gathering. As to the vertical distribution of group number of soi coleopterans, Leymus chinensis community, Leymus chinensis + Chloris virgata community and Puccinellia tenuiflora community appeared obvious nature of surface gathering. The trend of dynamic change of different soil layers'individual number and group number of soi coleopterans was different, The change scope of the first layer was larger than the others.The research of the correlation between the dynamic change of soi coleopterans community in leymus chinensis grassland and environmental elements showed that the factors influenced the change of soi coleopteran community of leymus chinensis grassland were soil and climate factors ,and the former was more important than the latter.