Characteristics And Seasonal Dynamics Of Soil Animal Community In Small Watershed At Jinfouping In Wuqi County,Shaanxi Province

In order to study the characteristics of soil fauna in the Jinfoping small watershed of Wuqi under different vegetation types and the changing law of soil fauna with seasonal changes,this paper selects the small watershed of Jinfoping in Wuqi County as the research area,and takes the soil fauna in the watershed as the research object.Nine sample plots were set up with different vegetation types.Large soil animals were selected by hand,and medium and small soil animals were selected by funnel method.Sampling and classification and identification of captured soil animals.In order to understand the characteristics of soil animal community in the study area and monitor its seasonal dynamic change characteristics,the research results can provide some basic data for the distribution of soil animal community in the small watershed of the Loess Plateau in northern Shaanxi.The relevant results are as follows:(1)A total of 8,136 soil animals were captured during the annual survey in the study area,belonging to 71 groups of 4 phyla,10 classes,28 orders,and 71 groups of4 phyla,10 classes,28 orders.The dominant groups Oribatida,Prostigmata,Collembola,as well as common groups Diptera,Coleoptera,Hymenoptera,Araneae,Polydesmida,Rhabditia,Hemiptera,and Lepidoptera represent the soil in the study area.The community composition of the animal as a whole.Twenty-two rare taxa,such as Scydmaeninae,Lecaniidae,Oxyopidae,and Theridiidae,which have high requirements on climate,vegetation and other environmental conditions,only appeared in one season.(2)In the horizontal direction,based on the overall capture of the four seasons,the number of soil fauna in different vegetation types is mixed forest>arbor pure forest>shrub pure forest>grassland;individual density is shrub pure forest>arbor pure forest>mixed forest>grassland.In the vertical direction,the soil animal community and individual density of each plot showed obvious surface aggregation characteristics.There were differences in the surface aggregation degree of different vegetation types.The above-ground tree and shrub vegetation had little effect on the vertical distribution of soil animals.(3)There are significant differences in the α-diversity characteristics of soil animals among different vegetation types.The Shannon-Wiener diversity index shows that the arbor pure forest > mixed forest > grassland > shrub pure forest.The comprehensive analysis of the diversity index characteristics shows that the arbor pure forest is better than other vegetation types.The composition of soil fauna is the most abundant,and the distribution of soil fauna in the shrub pure forest is the most scattered.(4)The seasonal dynamics of soil animal community showed that the number of groups in winter was significantly lower than that of the other three seasons(P<0.05),and there was no significant difference in the number of groups with seasonal changes in spring,summer and autumn.The individual density of autumn was significantly higher than that of the other three seasons(P<0.05),and the individual density of most soil animals reached the highest value in autumn.The vertical distribution of soil animals was the highest in summer and lowest in winter.Shannon-Wiener index and Margalef index summer>spring>autumn>winter,Pielou index in autumn was significantly lower than the other three seasons(P<0.01).With the change of seasons,the similarity characteristics of soil animals in various plots fluctuated in different amplitudes.In winter,the similarity of soil animal communities in various plots was the highest,and the degree of distribution and aggregation of soil animals was the highest.In summary,the results of this study show that the soil animal community in the Wuqi small watershed is diverse,and the forest and grass vegetation is improved during the process of returning farmland to forest(grass),and then a relatively rich soil animal community is gradually formed.There were differences in soil animal community structure richness in different habitats,and the soil animal structure in arbor forest and mixed forest was more stable.The individual density of soil animals reached the highest in autumn,and the diversity index reached the highest in summer.