Experimental design to explore effects soil legacy and nitrogen on Rhus typhina and Ailanthus altissima in monoculture and mixture. The experiment had two parts: one was a field soil collection and the other one a greenhouse experiment. The soil samples were collected in Zhenshan Mountains, Shandong Province, China (37°31'28"N, 121°21'8"E). The two soil samples included one where invasive R. typhina had grown and the other without this species. The brown pots represented the soil inoculated soil from R. typhina community. The grey pots represented the soil inoculated soil from R. typhina community. N0: no nitrogen addition; N8: moderate nitrogen addition (8 N m-2 year-1); and N20: high nitrogen addition (20 N m-2 year-1).