Abstract:
Global changes will affect not just mean environmental conditions but also temporal environmental fluctuations. Many studies emphasize that resource fluctuations contribute to the successful of invasive alien plant species, but the impact of resource fluctuations on the biomass allocation to aboveground and belowground part of invasive plants remains largely unclear. We used invasive plant
Erigeron canadensis L. as the target species and set up four different nutrient additions (constant low, constant high, multiple pulses and single pulse) to investigate how invasive alien plants respond to changes in resources availability in the environment. We found that aboveground biomass, belowground biomass, chlorophyll content and specific leaf area of E. canadensis were significantly increased under high nutrient conditions compared to low nutrient conditions, although the root-shoot ratio decreased significantly. In all high nutrient treatments, the temporal pattern of nutrient supply also affected plant biomass production, root-shoot ratio and specific leaf area. Particularly, we found that single pulse treatment greatly inhibited the aboveground biomass and promoted belowground biomass, while multiple pulses treatment had a slightly tendency to promote the total biomass of invasive plants and significantly increase the specific leaf area. Our study shows that the environmental resource fluctuation changes the growth strategy of invasive plants and thus affects their performance, but the fluctuation of nutrient availability does not significantly promote the growth of invasive plants.