关键词: 太湖, 土壤动物, 生物多样性, 典范对应分析, 土壤理化性质

Abstract:

The soil fauna, as an important part of the wetland ecosystem, has attracted more and more attention. They play a vital role in the material circulation and wetland restoration processes. In August 2010, we investigated soil animals in different vegetation covers (A: Rumex acetosa lakeshore, B: Tree and shrub lakeshore, C: Crop lakeshore, D: Natural reed lakeshore) at Lake Taihu lakeshore wetland with Tullgren and Baermann's methods. A total 537 soil animal individuals were extracted and classified into four phyla, and 59 taxonomic groups. R. acetosa lakeshore (A) had the lowest density of soil animals (4 017 ind·m^-2), while tree and shrub lakeshore (B) had the highest density of soil animals (14 496 ind·m^-2). There were differences in soil animal community space similarity over the four vegetation cover types, suggesting that vegetation cover types had an impact on soil animal community species composition, richness of communities and the number of dominant groups. The horizontal distribution pattern of the soil animals in the number of individuals was B > C> D > A. The canonical correspondence analysis (CCA) was used to analyze the correlations between the distribution of soil animal communities in the different caver types and the soil moisture content, pH, conductivity, soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), or soil temperature. The result showed that different soil animals had differential responses to different environmental factors, and various soil factors had to different degrees impact on the distribution of soil fauna. Among them, total phosphorous (TP) had a relatively strong impact on the Carabidae larvae, Ceratopogonidae larvae and Liocranidae, while electric conductance (Cond) had strong impact on Neanuridae. SOM had a greater impact on Isotomidae, pH had a greater impact on Onychiuridae, and soil temperature had a greater impact on Enchytraeidae. This study would provide scientific reference for wetland restoration.

Key words: Lake Taihu, soil fauna, biodiversity, canonical correspondence analysis (CCA), soil physical and chemical properties