Abstract: Soil animals are an important component of ecosystem and can indicate the ecological condition of the region. To understand the effects of flooding and vegetation mowing on the composition and diversity of soil macrofauna community in reservoir bench, we carried out investigation in three different sampling areas, including the flooding area, flooding and mowing area, and the untreated area in Qingcaosha Reservoir bench in September 2018. Soil macrofauna, vegetation, and sediment were collected and analyzed. The results showed that different disturbances had different effects on the composition and diversity of soil macrofauna community. Species composition of soil macrofauna community in the flooding area was different from that in the untreated area, with a decrease of Hymenoptera species and an increase of Coleoptera species. Moreover, the Shannon diversity index of soil macrofauna community in the flooding area was significantly higher than that in untreated area (P<0.05). Flooding together with vegetation mowing had a negative effect on soil macrofauna community. Compared to the flooding area and the untreated area, the richness of soil macrofauna species in the flooding and mowing area was substantially decreased. The two dominant species in the flooding area and the untreated area, Porcellionides sp. and Plectoropis sp., were not found in the flooding and mowing area. The density, Shannon diversity index, Margalef richness index and Pielou evenness index of soil macrofauna in the flooding and mowing area were significantly lower than those in the other two areas (P<0.05). The abundance and biomass of the soil macrofauna in the untreated area were significantly correlated to the combination of 0-2 cm soil particle median diameter, 2-5 cm soil total phosphorus, nitrogen and carbon content, and plant density (P<0.05). However, such significant correlations were not observed in the other two areas (P>0.05). Beyond their direct effects on soil macrofauna, flooding and vegetation mowing can modify the relationships between habitat factors and soil macrofauna.

Key words: flooding, vegetation mowing, Qingcaosha Reservoir, soil macrofauna community.