Variations of ground vegetation and arthropod communities under simulating precipitation in sandy grassland

In order to reveal the response of vegetation and arthropods community to simulating precipitation, the soil properties, vegetation and arthropods characteristics of sandy grassland in desert steppe of Ningxia were evaluated under different treatments including natural precipitation (control), 20% more simulating precipitation, 40% more simulating precipitation, 60% more simulating precipitation and 100% more simulating precipitation. There was no significant difference in soil, vegetation, and arthropods properties between the different treatment plots and prior experiment, which suggested the similarity of experiment plots and practicability of experimental design. After treatments, simulating precipitation had little effects on plant species richness. However, in the autumn, plant density with 40% more simulating precipitation was significantly (P0.05) lower than that with control, and plant height with 20% and 40% more simulating precipitation was significantly (P0.05) lower than that with control. Meanwhile, simulating precipitation also had little effects on arthropod abundance. In the autumn, the arthropod species richness with 20%, 60% and 100% more simulating precipitation were significantly (P0.05) higher than that with control. The present results suggested that the comprehensive consideration of all the factors including soil, vegetation and arthropods was necessary for experimental design. The plant abundance and height and arthropod species richness were relatively sensitive to the precipitation although there was time delay.