Effects Of Grazing And Exclosure On Arthropod Community Beneath Shrub Canopy And In Open Space In Sandy Land Ecosystem

Shrubs have significant effects on “Fertile island” and “Arthropod island” in the sandy ecosystem.The formation and evolution of shrubs “Fertile island” are closely related to the management of grassland and have more research,but there is little research on the effect of enclosure management on the distribution of arthropods(ie,“Arthropod island”)inside and outside the shrub.In our studies,Choosing two Caragana krshinskii shrub forestlands in eclosure and grazing management as sampling plots in Yanchi Country of Ning xia.We investigated composition,biodiversity and the spatial distribution of soil faunal community in shrub microhatitas under grazing and enclosure management on May,July and Octobor 2015.The main results as follows:1.Degradation of desert steppe to implement the management of enclosure,significantly improve the height and canopy of Caragana korshinskii shrubs,increased density and species of herbaceous vegetations beneath shrub canopy and in open spaces,and resulted in significant improvement in soil physical and chemical properties(P<0.05).But there was no significantl impact on the “Fertile island” intensity of Caragana korshinskii shrubs(P>0.05).2.The abundance of soil mesofauna community in open spaces of shrubs had no significantly difference between enclosure and grazing management(P>0.05),significantly decreased beneath shrub canopy in the autumn.In the sites,soil mesofauna community and main groups showed the “Arthropod island”(RII>0).Comparatigve to grazing plot,changing the soil mesofauna community and main groups,the relative interaction intensity(RII)of soil mesofauna community and main groups were changed after enclosure,but there was no significanlty difference(P>0.05).3.After implementation enclosure managment in deserted grassland,the ground-dwelling arthropod community had no significantly difference in open spaces(P>0.05).In the grazing plots,the Caragana korshinskii shrubs showed strong of “Arthropod island”of ground-dwelling arthropod(RII>0),mainly in the spring,lowered the indensity of “Arthropod island” after enclosure,but had no significantly difference(P>0.05).Most ground-dwelling arthropod showed the “Arthropod island”(RII>0).Meanwhile,because of the life habit of Formicidae lived in caves showed a reverse of pattern of “Arthropod island”(RII<0).The enclosure showed a reverse of pattern of “Arthropod island”(RII<0).Based on the above results,improving the index of soil properties and promoting the restoration of herbaceous after implementation enclosure managment in deserted grassland,having no significantly impact on “Fertile island”,soil mesofauna community and ground-dwelling arthropod community beneath shrub canopy and in open space.The interaction and adaptation between shrubs and animals in the long-term evolution can lead to the“Arthropod island”,which plays an important role in protenting the biodidiversity in desert areas.