Availability of nitrogen (N) regulates phosphorus (P) acquisition and plant growth. However, it is unclear how the growth and competitive ability of invasive plants grown in low P availability environment respond to elevated N deposition in the future. In this study, a diallel design was used to examine the competition between an invasive plant (Solidago canadensis) and a co-occurring native plant (Pterocypsela laciniata) exposed to three N levels: no N supply served as control level (0.00 mg kg-1; CK), low N level (45.00 mg kg-1; L-N), and high N level (135.00 mg kg-1; H-N). Hydroxyapatite (HAP) was used to simulate low P availability.
Results/Conclusions
The results showed that N addition significantly increased the growth of both S. canadensis and P. laciniata growing alone; however, the effect of N addition was reduced when intra or interspecific competition existed. N addition altered the competitive relationship between S. canadensis and P. laciniata under HAP condition, resulting invasive plant S. canadensis to outcompete native plant P. laciniata. Elevated N deposition may assist the expansion of S. canadensis to the northern China where hydroxyapatite widely exists in the calcareous soils.