Abstract: A greenhouse pot experiment was conducted to investigate the effects of soil fungi in native plants-dominated soil (NS) and Ambrosin artemisiifolia
-invaded soil (IS) on the growth of and interaction between invasive weed A. artemisiifolia and native plants. On NS, the biomass of A. artemisiifolia
 from monoculture A. artemisiifolia, mixed culture A. artemisiifolia and native plant S. viridis, and mixed culture A. artemisiifolia and native p
lant M. sativa in fungicide treatment was 46.7%, 39.1%, and 90.5% higher than that in non-fungicide treatment, respectively, but no significant difference was observed in the biomass of S. viridis and M. sativa between fungicide and nonfungicide treatments. On IS, compared with that in nonfungicide
treatment, the biomass of A. artemisiifolia from monoculture A. artemisiifolia in fungicide treatment was decreased by 44.3%. Fungicide application also decreased the biomass of the two native plants in mixed cultures, but the effect was not significant. The feedback of soil fungi in NS and IS on plant growth
and competition was further analyzed. In NS, there was a negative feedback of soil fungi on the growth of A. artemisiifolia, no matter in monoculture or in mixed culture; while in IS, the feedback on the growth of monoculture A. artemisiifolia became positive, and the negative feedback on the growth of mixed culture A. artemisiifolia became less. This study supplied some experimental evidences for the further research on the soil microbial mechanism during A. artemisiifolia invasion.

Key words: Land use change, Soil organic carbon, Concentration and inventory