A Preliminary Studies On The Community Characteristics Of Soil Oribatid Mites In South Of Urumqi

In order to explore the community structure characteristics of soil oribatid mites in four different land use types in the south of Urumqi,and investigate the relationship between the oribatid mites community with the environmental factors, the sampling sites selected for this study include four urban green lands with the different land use types in south of Urumqi, namely industrial area,greenland at roadside, natural forest and farmland from April to October in 2009. Soil oribatid mites which using morphological traits to clssify to genus level, and adoped of group number,community diversity ,abundance ,evenness,dominance and MGP analysis were used to study the commnity structure characteristics of soil oribatid mites. While the relationship between enviromental factors and soil oribatid mite communities was analysed, the main results were as follow:Total of 9019 soil oribatid mites were collected, and they belonged to 26 families,32 genus,among of them 8 families,16 genus were new records for the Xinjiang .The number and composition of soil oribatid mites under different land use types were different.The sequence of species numbers was :natural forest(26)>farmand(23) > grassland at roadside(21)>industrial area(19); The sequence of individual numbers was: natural forest(2663) > farmland(2330) > grassland at roadside(2049)>industrial area(1977).The dominant groups and characteristic genus from sampling areas were varied. The predominant groups were Nothrus and Scheloribates in the four different habitats.The seasonal change of soil oribatid mites community were different.The catches of soil oribatid mites reached the high level in September,whereas the low level in Apirl .The study showed that the vertical distribution of the soil oribatid mite individuals and group numbers have the characteristics of surface assembling.The sequence of Shannon-Wiener species diversity index (H) and Margalef abundance index(M):Natural forest>farmland>grassland at roadside>industrial area, respectively.The Pielou evenness index(E) : Natural forest>industrial area> grassland at roadside>farmland.The Simpson dominant index(C): Industrial area > grassland at roadside > farmland > natural forest.The MGP analysis indicated that the MGP I in four different land use types were O type,but the MGP II analysis were different in different habitats, industrial area was P type,whereas the other three land use types were O type.The Jaccard similarity index showed that the oribatid mite communities of industrial area and greenland at roadside were much similar, but soil mites community in natural forest and industrial area were moderately dissimilar,the soil oribatid mites community in the other three greenlands were moderately similar.The environmental factors have a different impact on the community of soil oribatid mites.With in a range, the correlation analysis of environmental data showed that the relativity between soil oribatid mite individuals and the water content have nagetive correlation(p<0.05) , and the temperature and soil oribatid mites individual have a positive correlation(p<0.01) .The pH value and organic matter have positive correlation with soil oribaid mites community(p>0.05).Through comprehensive analyzing of the experimental results,the genus of Nothrus, Tectocepheus and Rhysotritia were preliminary determined to the bioindicator for soil environmental quality in the south of Urumqi .The result showed that the community structure and diversity of soil oribatid mites in four different land use types were heterogenious.So,the change in community structure of soil oribatid mites using as bioindicator for the degree of the soil environmental quality.