SUPPORTING INFORMATION
TABLE S1 The elevation and coordinates of the seed collection locations of G. quadriradiata central and edge populations in China.
TABLE S2 The dependence of maximum net photosynthetic rate (P max), leaf nitrogen concentration (LNC), and leaf phosphorus concentration (LPC) of Galinsoga quadriradiata on the experimental treatments based on GLMM. The invasive plant population types (PopType): edge population and central population. Nitrogen treatments (NTC): deionized water, 3 g L-1NH4NO3 solution, and 6 g L-1 NH4NO3 solution. Culture type (Culture): single and mixed. Competitor types (CompType): mixed with new competitors and mixed with old competitors. The bold value indicates that it is statistically significant at α = 0.05 level.
FIGURE S1 Comparison of the total mass of the central and edge populations of G. quadriradiata under different competitor types. The invasive plant population types: edge population and central population. Culture and competitor types: single-culture with no competitor (None), mixed with new competitors (New competitor), and mixed with old competitors (Old competitor). The data of different nitrogen treatments summed together. Different letters indicate significant differences at p < 0.05. Values are means ± SE.
FIGURE S2 Comparison of the relative competition index (RCI) of the central and edge populations of G. quadriradiata under nitrogen treatments. The invasive plant population types: edge population and central population. Three levels of nitrogen treatments (NTC): treated with deionized water (Ambient N), 3 g L-1 NH4NO3 solution (Low N), or 6 g L-1NH4NO3 solution (High N). The data of no competitors and different competitors summed together. * indicate significant differences at p < 0.05. Values are means ± SE.
FIGURE S3 Comparison of the number of capitula per plant (NCP) of the central and edge populations of G. quadriradiata under different competitor types. The invasive plant population types: edge population and central population. Three levels of nitrogen treatments: deionized water (Ambient N), 3 g L-1 NH4NO3solution (Low N), and 6 g L-1NH4NO3 solution (High N). Culture and competitor types: single-culture with no competitor (None), mixed with new competitors (New competitor), and mixed with old competitors (Old competitor). The data of different nitrogen treatments summed together. Different letters indicate significant differences at p < 0.05. Values are means ± SE.
FIGURE S4 Comparison of the Leaf construction cost per unit of mass (CCmass) of the central and edge populations ofG. quadriradiata under nitrogen treatments. The invasive plant population types: edge population and central population. Three levels of nitrogen treatments (NTC): deionized water (Ambient N), 3 g L-1 NH4NO3 solution (Low N), and 6 g L-1NH4NO3 solution (High N). The data of no competitors and different competitors summed together. * indicate significant differences at p < 0.05. Values are means ± SE.
FIGURE S5 Comparison of the maximum net photosynthetic rate (P max) of G. quadriradiata under different treatments. Competitor types: mixed with new competitors (New competitor), and mixed with old competitors (Old competitor). Culture type: single-culture (Single) or mixed with competitors (Mixed). The data of different nitrogen treatments summed together. Different letters indicate significant differences at p < 0.05 in each subgraph. Values are means ± SE.