Study On The Community Structure And Ecological Adaptation Of Soil Scarab Under The Condition Of Different Water-Soil Erosion Controlling Methods In Huangfu-chuan Watershed

The study plots were located in Wufendi and Yangquan ravine, Huangfu-chuan watershed in Inner Mongolia.Five controlling methods of water-soil erosion,i.e.,pine woodland,aspen woodland,artificial shrub,artificial-planded weadow and abandoned cropland were sampling sites.And farmland,grassland and degenerated grassland were controlling sites.Soil sampling and bait trap were used to collect soil scarabs in 2007 - 2008.The soil scarab community construction,community similarity,species diversity, niches and ecological adaptation were analysed.The main results as follows.1.A total of 6 999 soil scarabs belonging to 4 families,12 genus and 21 species were captured.Among them,1 041 were of shytophagous scarab imago and larvea belonging to 2 families,6 genus and 7 species.The dominant species are Serica orientalis and Diphycerus davidis.And 5 958 were of coprophagous scarabs belonging to 2 families,6 genus and 14 species. The dominant species are Aphodius rectus and Onthophagus gibbulus.2.Compared to control sites,the individual numbers and biomass of shytophagous scarab were increased under in different water-soil erosion controlling methods sites.But the individual numbers of coprophagous scarabs were not significant increase.And the biomass of them were decrease on the contrary.In different water-soil erosion controlling methods sites,the dominant species of shytophagous scarab communities were same as that of in control sites,the number of dominant species of coprophagous scarab communities were higher than that of in control sites.It was especially that the community of coprophagous scarab in pine woodland was monodominant community which with Onthophagus sinicus. 3.Based on the analysis of community similarity,the soil scarab communities in different sampling sites can be divided into four kinds.The first kind were distributed in grassland and degenerated grassland.The second one were distributed in aspen woodland,artificial shrub and farmland.The third one were distributed in artificial-planted meadow,farmland and abandoned cropland.The fourth one were distributed in pine woodland.4.As the different water-soil erosion controlling methods put in practice in Wufendi ravine,the diversity of shytophagous scarab community was significantly inhanced comparing to control sites.But the diversity of coprophagous scarab community was not significantly changed.5.The results that from the partial correlation and CCA between soil scarab community and environmental factors indicated that the main environmental factors which affected soil scarabs were water content of soil, total phosphorus of soil,condition of vegetation and available phosphorus of soil.