Carabid community and its fluctuation in farmland of salinity transforming area in the North China Plain:a case study in Quzhou County, Hebei Province
华北盐渍化改造区农田步甲群落及其动态研究:以河北省曲周县为例

In 1996 and 1997, a carabid community and its fluctuation were studied by the pitfall method in the salinity transforming area in Quzhou County, Hebei Province, China. The community consists of 19 species belonging to 8 genera. Harpalus is the dominant genus and ranks the first in abundance. As a whole, the carabid fauna in this area is simple, having relatively few species and genera. The dominant species are Harpalus simplicidens, H. griseus and H. tridens. Considering the monthly fluctuation of carabid abundance, it reaches a maximum in September, and falls to a minimum in October. The fluctuation of carabids differs among different crop-planting patterns, and is affected to an extent by the changes of the landscape and agricultural activities. Field margins are shelters for carabids where they tend to gather, and these margins play a pivotal role in protecting the carabids. Carabid density in field margins is higher than that in adjacent farmlands, and the monthly fluctuation range there is also narrower.