Abstract: Solidago canadensis, a notorious invasive weed species highly dependent on AM fungi (AMF), has been spreading rapidly in eastern China. At present, nitrogen deposition has become one of the most concerned environmental issues, but few studies have focused on the effects of AMF and nitrogen deposition on the growth of S. canadensis. In this paper, a greenhouse pot culture experiment was conducted to study the effects of inoculating AMF on the growth and biomass accumulation of S. canadensis seedlings under different nitrogen application levels. Inoculating AMF had significant positive effects on the leaf number, biomass accumulation, and AMF colonization rate of seedlings. Also, with the extension of the treatment period, the promotion effects of AMF on the plant height and leaf number were increasing. However, both nitrogen deposition and the interaction between AMF and nitrogen deposition had no significant effects on the seedlings’ growth. Different nitrogen application levels had definite influence on the effects of AMF. It was suggested that AMF had significant promotion effects on the invasion of S. canadensis, and the variation of exogenous nitrogen supply level determined the degree of host plant benefit derived from AMF.

Key words: water level fluctuation zone, canyon landform area., soil chemical property, temporal and spatial dynamics, Three Gorges Reservoir