Elevated nitrogen deposition may advance invasive weed, Solidago canadensis, in calcareous soils

Aims change in nitrogen(N)availability regulates phosphorus(P)acquisition and potentially alters the competition among native species and invasive weeds.this study determines how current and pro-jected N deposition affect the growth,the intraspecific and interspe-cific competitive ability of native and invasive plants in calcareous soils with low P availability.Methods A controlled greenhouse experiment was conducted using spar-ingly soluble hydroxyapatite(HAP)to simulate the calcareous soils with low P availability.the growth and competitive intensity be-tween an invasive weed(Solidago canadensis)and a native weed(Pterocypsela laciniata)exposed to two levels of N addition repre-sentative of current and future N deposition in china were experi-mentally determined.Important Findings P acquisition and the growth of both S.canadensis and P.laciniata growing alone significantly increased with increasing N level.However,the effect of N addition was reduced when intraspecific or interspecific competition existed.N addition altered the com-petitive relationship between S.canadensis and P.laciniata allowing S.canadensis to out-compete P.laciniata due to variation in P ac-quisition from HAP.Elevated N deposition might assist the invasion of S.canadensis in the widely distributed calcareous soils under environmental changes.