Characteristics Of Soil Fauna Community Under Different Plant Communities In Dajinshan Island

As the largest island in the “Marine Ecological Nature Reserve in Jinshan three island”,Dajinshan Island has a living environment similar to natural level and less human disturbance.It is the most abundant wild natural plant in Shanghai.As an integral part of forest ecosystems,soil fauna play an important role in promoting the material and energy cycle of forest ecosystems.In this study,eight typical natural plant communities(Quercus acutissima community,Mallotus japonicus community,Zanthoxylum ailanthoides community,Celtis sinensis community,Euonymus maackii community,Cyclobalanopsis glauca community,Cinnamomum japonicum community,Machilus thunbergii community)in Dajinshan Island were selected in autumn(October 2017),winter(December 2017),spring(March 2018),summer(June 2018)survey of soil fauna and soil physicochemical properties.The conclusions of this study were as follows:1.In this study,a total of 17181 soil fauna individuals were collected,belonging to 5 phyla,14 classes and 34 groups,of which the dominant groups were Nematode,Arcarina and Collembola.The dominant species of soil fauna in litter were Arcarina and Collembola.The common groups were Isopoda,Leopdaoptera larvae and Coleoptera larvae;the dominant species of soil-macro fauna were Isoptera,Hymenoptera and Isopoda.The common groups were Diplura,Chilopoda,Araneae,Diplopoda,the diptera larvae,Leopdaoptera larvae,Coleoptera larvae and Coleoptera;the dominant group of soil meso-and micro-fauna were Nematode,Arcarina and Collembola,the rest are rare groups.2.In terms of vertical distribution,soil fauna density showed obvious surface aggregation,and soil fauna density in 0-5cm,5-10 cm,10-15 cm and 15-20 cm soil layers showed a decreasing trend.In terms of seasonal dynamics,The density of soil fauna in litter,soil macro-fauna and soil meso-and micro-fauna were highest in summer and lowest in winter.The soil fauna in litter had the highest group number in summer,the spring and winter were lower.The group number of soil-macro faunawas highest in autumn and lowest in winter.The group number of soil meso and micro-fauna was highest in autumn,and the other three seasons had the same group number.The diversity level of soil fauna in litter was highest in summer,and were lower in spring and winter.The diversity level of soil macro-fauna and soil meso and micro-fauna were highest in autumn,and were lower in spring and winter.3.According to density,group and community diversity index,the soil fauna diversity level in evergreen broad-leaved forest was higher than that of deciduous broad-leaved forest in this study.The density and group number of soil fauna in litter and soil meso and micro-fauna in evergreen broad-leaved forest were higher than that of deciduous broad-leaved forest,and the group number of soil macro-fauna in the evergreen broad-leaved forest was equal to deciduous broad-leaved forest.The density and group number of soil-macro fauna in evergreen broad-leaved forest was higher than that of deciduous broad-leaved forest.The Shannon-Wiener diversity index,Pielou evenness index and Margalef richness index of soil fauna in litter and soil meso-and micro-fauna in evergreen broad-leaved forest were higher than those of deciduous broad-leaved forest.The Shannon-Wiener diversity index and the Margalef richness index of soil macro fauna were close to those of deciduous broad-leaved forest,and the difference was not significant.Comprehensive density,group and community diversity index,among different community types in evergreen broad-leaved forest,the diversity of soil fauna community in Cyclobalanopsis glauca community and Machilus thunbergii community were higher,and Cinnamomum japonicum community was lowest.Among different community types in evergreen broad-leaved forest,the group number of soil fauna in litter and soil meso and micro-fauna in Cyclobalanopsis glauca community were highest,and Cinnamomum japonicum community was lowest.The group number of soil macro fauna in Machilus thunbergii community was highest,and that of Cinnamomum japonicum community was lowest.The density of soil fauna in litter,soil macro fauna and soil meso and micro-fauna in Machilus thunbergii community were highest,and the density of soil fauna in litter and soil macro fauna in Cinnamomum japonicum community were lowest,and the density of soil meso and micro-fauna inCyclobalanopsis glauca community were lowest.Comprehensive density,group and community diversity index,among different community types in deciduous broad-leaved forest,the soil fauna diversity in Zanthoxylum ailanthoides community was highest,and the soil fauna in Euonymus maackii community was lowest.Among different community types in deciduous broad-leaved forest,the soil fauna density and the group number in Zanthoxylum ailanthoides community were in the forefront,and the group number of soil fauna in Euonymus maackii community was lowest.In terms of community diversity index,the Shannon-Wiener diversity index and the Margalef richness index of soil fauna in Zanthoxylum ailanthoides community were in the forefront,and the Shannon-Wiener diversity index and Margalef richness index in Euonymus maackii community were lowest.In terms of density,group and community diversity index,4.In terms of the effect of physicochemical properties on soil animal density,the total density,Nematode density,Arcarina density and Collembola density of soil meso-and micro-fauna were positively correlated with water content,and the bulk density was a certain degree.There was a significant positive correlation between the total density of soil meso-and micro-fauna and Nematode density and the organic matter(p<0.05).The Arcarina density and Collembola density showed a positive correlation with the organic matter.