Effects Of Different Grazing Intensities On Soil Fauna Communities In A Stipa Breviflora Desert Steppe

In this study,we investigated community characteristics of soil meso-fauna,macro-fauna and ground-dwelling arthropods,using Tullgern funnel,hand sorting and pitfall traps method,in a Stipa breviflora Desert Steppe of Siziwang Banner under different grazing intensities from 2014 to 2015.Correlation between soil fauna and environmental factors were analyzed.We also investigated soil faunal community composition,diversity, vertical distribution under different grazing intensities. The results show:1.A total of 145 individuals were captured from the soil meso-fauna,and classified into 1 phyla,4 classes,11 orders,54 families,54 groups.There was no dominace family the soil meso-fauna group.A total of 3117 individuals were captured from the soil macro-fauna,and classified into 1 phyla,3 classes,9orders,34 families,40 groups.The community was found to be dominated by Formicidae.A total of 20152 individuals were captured from ground-dwelling arthropods,and classified into 1 phyla,2 classes,9orders,48 families,54groups.The community was found to be dominated by Formicidae and Carabidae.2.There was a trend,both soil fauna number and group decreased with grazing intensity increased.Grazing significantly reduced soil meso-fauna group and density in a Stipa breviflora Desert Steppe. Grazing significantly reduced soil macro-faunal density.Moderate grazing and heavy grazing significantly reduced soil macro-fauna groups.Moderate and heavy grazing significantly reduced the number of individuals in ground-dwelling arthropods.Grazing significantly reduced the group number of ground-dwelling arthropods;soil meso-fauna,macro-fauna and ground-dwelling arthropods are as follows:control(CK)> light grazing(LG)> moderate grazing(MG)> heavy grazing (HG)3.Soil fauna in Stipa breviflora Desert Steppe obviously distributed at surface layer.Soil meso-fauna number in control plot at 0-10cm were significantly higher than 10-20cm layer.There were no significant difference between meso-fauna individual and group number in each grazing plots,so grazing has changed the vertical distribution of meso-fauna.Macro-faunal density and group number in control,light at 0-10cm were significantly higher than that of 10-20cm layer.There was,however,no significant difference between individual and group number in moderate.grazing and heavy grazing treatment.Therefore, moderate grazing and heavy grazing has changed the vertical distribution of soil macrofauna.4.Grazing has on significant effect on soil fauna Simpson dominance,diversity, evenness index (P>0.05),while moderate,heavy grazing significantly reduced density-group index in soil fauna of Desert Steppe (P<0.05)...