Comparison between the exotic Coreopsis grandiflora and native Dendranthema indicum across variable nitrogen deposition conditions

Functional trait values and phenotypic plasticity are the two main factors associated with the invasiveness of exotic plants. In this study, we aimed to determine the effects of plant functional traits and phenotypic plasticity on the invasiveness of exotic species under different nitrogen (N) deposition conditions, using the seedlings of the exotic Coreopsis grandiflora and the native Dendranthema indicum species. The results showed that N deposition increased the relative growth rate of height, total biomass, height, crown area, water use efficiency, leaf area, leaf biomass, root biomass, net photosynthesis rate, and leaf nitrogen to phosphorus ratio of the two species. Both C. grandiflora and D. indicum showed significant differences in all functional traits except photosynthetic nitrogen use efficiency. At low N levels, the performance (total biomass) in C. grandiflora was similar to that of D. indicum. However, at high N levels, the performance of C. grandiflora was greater than that of D. indicum, which is consistent with the master-of-some strategy of exotic plants. We discovered that the differences in the functional traits and phenotypic plasticity between the two species under high N environments promoted the rapid growth of C. grandiflora. Furthermore, the functional trait values of C. grandiflora made a greater contribution than phenotypic plasticity to its superior performance. Therefore, our findings provide insights into the mechanism employed by exotic species to facilitate invasion under variable N deposition conditions.

Automated summary

Functional trait values and phenotypic plasticity are two important factors affecting the invasiveness of exotic plants. This study examined the effects of plant functional traits and phenotypic plasticity on invasiveness under different nitrogen deposition conditions using seedlings of exotic Coreopsis grandiflora and native Dendranthema indicum species. The results showed that nitrogen deposition increased the growth rate of various functional traits in both species. At high nitrogen levels, C. grandiflora outperformed D. indicum, consistent with the master-of-some strategy of exotic plants. The differences in functional traits and phenotypic plasticity under high nitrogen environments contributed to the rapid growth of C. grandiflora, with functional trait values playing a larger role than phenotypic plasticity. These findings provide insights into the mechanisms used by exotic species to facilitate invasion under varying nitrogen deposition conditions.