Structural characteristics of the soil fauna community in beach wetlands of the Poyang Lake region

We examined the soil fauna community composition and structure of Poyang Lake beach wetlands using the modified Tullgren and Baermann methods during September and December 2015. A total of 3755 individuals were obtained from 2 samplings, which were found to belong to 7 classes, 8 orders, 3 suborders, and 17 families. Among these, the Oribatida, Prostigmata, Nematoda, and Onychiuridae were dominant. The functional groups of soil animals included omnivores, saprozoics, predators, and phytophages. Analysis results of the soil fauna composition and diversity showed that the soil animals were mainly concentrated at the 0-10 cm depth, presenting as a significant surface convergence phenomenon. The numbers of individual soil animals differed significantly between sampling sites (P < 0.05), with the beach wetland in Lianhu Township having the highest numbers of individuals and groups. The effect of water level variability on numbers of soil animals was not significant (P > 0.05). Habitat type and sampling time both had highly significant effects on diversity and evenness (P < 0.01), and significant effects on species richness (P < 0.05). During water level changes in Poyang Lake, the individual number, group number, and diversity of the soil animals were closely linked to the sampling site. These results provide basic data for further studies on soil fauna ecology in Poyang Lake beach wetlands.