Effects of elevated CO2 on photosynthetic traits of native and invasive C3 and C4 grasses (2012 and 2013, south-central Ontario, Canada)

We assessed the responses of photosynthetic traits of native and invasive C3 and C4 grasses to atmospheric carbon dioxide levels. We used three levels of CO2 (390, 700, and 1000 ppm) in a closed chamber experiment and tested 16 grass species (eight C3 plants and eight C4) classified as noninvasive or invasive. We tested the hypotheses that invasive species would be more productive under elevated CO2 and that the strongest responses would be seen in C3 plants.