Abstract: As the important driving factors of global change, changing precipitation and nitrogen (N) deposition play a key role in affecting our terrestrial ecosystem. However, most previous stu-dies focused on the aboveground plant community. The soil fauna, especially the ground-active arthropods were poorly understood. Using field manipulative experiment, this paper studied the effects of increased precipitation and N deposition on the soil ground-active arthropods in an old-field ecosystem of the Huanghuihai Plain. The results showed that the increased precipitation significantly enhanced the soil arthropods population density and the number of groups by 66.9% and 27.8%, respectively. Nitrogen deposition had minor effect on soil arthropods population density and number of groups, but significantly increased the formicidae and decreased the collembolans. Our results indicated the changing precipitation was the more important factor than the N deposition to restructure the soil surface arthropod community by increasing soil moisture and stimulating plant growth in the old-field of north China plain.

Key words: nitrogen deposition, population density, community structure, soil surface arthropods, changing precipita-tion