Soil Fauna Communities In Stipa Breviflora Desert Steppe Response To Water And N Treatment

Understanding the effects of water and nitrogen treatment on soil fauna community in desert steppe,the Stipa breviflora desert steppe of Siziwang Banner used as the research object,modified Tullgren and trap capture method were used to investigate the main groups of soil meso-and micro-fauna and arthropod community.and the community composition,main groups,community diversity,vertical distribution and Monthly dynamic characteristics of soil fauna,and the correlation between soil fauna and soil environmental factors was also analyzed,under the nitrogen addition and precipitation change,in 2014 and2015.The results show that:(1)In Stipa breviflora desert steppe of Inner Monggolia,total of 654 individuals were captured,and classified into 4 phyla,10 orders 47 families.Collembola,Arachnida and Insecta were the major groups.The community was found to be dominated by Neanoridae and Isotomidae.There were 2851 arthropods captured.and classified into 2 phyla,9 orders39 families.The community was found to be dominated by Carabidae and Formicidae.total of 786 individuals soil meso-and micro-fauna were captured,in 2015.and classified into 4 phyla,8 orders 36 families.Collembola,Arachnida and Insecta were the major groups.The community was found to be still dominated by Neanoridae and Isotomidae.There were 3747 arthropods captured.and classified into 2 phyla,9 orders 39 families.The community was found to be dominated by Carabidae,Carabidae Larve and Formicidae.(2)Water addition and Water addition combined with N addition stimulated the individuals of soil meso-fauna in desert steppe in 2014.Rainfall removal and rainfall removal combined with N addition reduced individual of soil fauna,Moreover,the interaction of water and nitrogen had a significant effect on the number of individuals of soil meso-fauna.In the experiment of nitrogen gradient in 2015,the soil fauna individuals were occupied largest number in the gradient N5,but the group richness had small changes.The interaction of water and nitrogen is also more obvious than that of single treatment.(3)The diversity index of soil meso-and micro-fauna and arthropods were did not show significant difference of Stipa breviflora desert steppe in 2014,soil meso-and micro-fauna diversity index significantly increased in precipitation nitrogen treatmentcompared with CK,the diversity index of arthropods in precipitation nitrogen treatment was significantly higher than the nitrogen treatment,in 2015.(4)Soil meso-and micro-fauna communities in Stipa breviflora desert steppe had obvious surface assembly,individual number in all treatment of 0~10 cm was significantly higher than 10~20 cm(P<0.05).The surface-aggregation does not changed under the water and N treatment.(5)The monthly dynamic changes of soil meso-and micro-fauna and arthropods in2014: August > July > June > September,In 2015,the quarterly dynamic changes of soil meso-and micro-fauna and arthropod individuals were : July >April> October.