Fig. 2From: Effects of elevated CO2 on photosynthetic traits of native and invasive C3 and C4 grassesThe effect of CO2 concentration (ppm), photosynthetic mechanism, and invasive status on a specific leaf area, b leaf N, and c leaf C:N ratio (mean ± SE). Asterisks represent the degree of significance between invasive status: †P < 0.10, *P < 0.05, **P < 0.01, ***P < 0.001Back to article page