Diversity Of Soil Fauna Communities Under Different Vegetation Types In Zhoushan Islands

Soil fauna can promote material circulation and energy flow in island ecosystem,this is very important.In this study,a total of 38 islands in Zhoushan Archipelago were selected as the research objects,with an area of 0.005～97.9km~2 and a nearest distance of 4.5～104.97km from the mainland.Soil fauna communities under typical vegetation types on the islands were investigated in June,July,August and September,2019.The main results are as follows:1.A total of 20,706 soil animals were captured,belonging to 5 phyla,14 classes,and 36 groups.The dominant groups were Nematode,Acarina and Collidata.The dominant groups in the litter layer were Acarina and Collimata,and the common groups were Larva of Lepidoptera,Arachnida,Hymenoptera and Diptera.Among the small and medium-sized soil animals in the soil layer,the dominant groups were Nematodes,Acarina and Collimata,the common groups were Lepidoptera larva,Arachnida and Rotifers,and the rest were rare groups.2.For soil fauna in the litter layer,the density and group number of soil fauna in the forest community were higher than those in the shrub community.The diversity of soil fauna in litter layer of forest community was higher than that of shrub community.In terms of community similarity,the soil fauna community in the forest litter layer and the soil fauna community in the shrub litter layer reached a moderate dissimilarity.Among different forest types,the density and number of soil fauna in litter layer were the highest in evergreen forest,and the lowest in deciduous forest.The diversity of soil fauna community in litter layer of evergreen forest was higher than that of evergreen and deciduous mixed forest and deciduous forest.In terms of community similarity,soil fauna communities in litter layer of evergreen forest and deciduous forest were moderately dissimilar.In terms of community composition of different shrub types,the density and number of soil fauna in litter layer of evergreen shrub were the highest,while that of deciduous shrub was the lowest.The diversity of soil fauna community in litter layer of evergreen shrub is higher than that of evergreen and deciduous mixed shrub and deciduous shrub.In terms of community similarity,soil fauna communities in litter layer of evergreen shrub and deciduous shrub reached moderate dissimilarity.3.For small and medium-sized soil fauna in soil layer,the density and group number of small and medium-sized soil fauna in forest community were higher than those in shrub community.The diversity of small and medium-sized soil fauna in forest community was higher than that in shrub community.In terms of community similarity,the community of small and medium-sized soil fauna in forest soil layer and shrub soil layer reached medium dissimilarity.Among the different forest types,the density and number of small soil fauna were the highest in evergreen forest and the lowest in deciduous forest.The diversity of small soil fauna in evergreen forest was higher than that in evergreen and deciduous mixed forest.In terms of community similarity,the communities of small and medium-sized soil fauna in evergreen forest layer were moderately dissimilar to those in deciduous forest.In terms of community composition,the density and number of small and medium-sized soil fauna in evergreen shrub were the highest,while that in deciduous shrub was the lowest.The diversity of small and medium-sized soil fauna and community in evergreen shrub is higher than that in evergreen and deciduous mixed shrub.In terms of community similarity,the communities of small and medium-sized soil fauna in the soil layer under different shrub types were moderately similar.4.The density and group number of soil fauna in the litter layer and the small and medium-sized soil fauna in the soil layer under different vegetation types were positively correlated with the island area and negatively correlated with the distance from the mainland.With the increase of island area,the level of soil fauna community diversity tended to increase,and with the increase of distance from the mainland,the level of soil fauna community diversity tended to decrease.