Productivity responses of Acer rubrum and Taxodium distichum seedlings to elevated CO_2 and flooding

摘要

Elevated levels of atmospheric CO_2 are expected to increase photosynthetic rates of C_3 tree species, but it is uncertain whether this will result in an increase in wetland seedling productivity. Separate short-term experiments (12 and 17 weeks) were performed on two wetland tree species, Taxodium distichum and Acer rubrum, to determine if elevated CO_2 would influence the biomass responses of seedlings to flooding. T. distichum were grown in replicate glasshouses (n=2) at CO_2 concentrations of 350 or 700 ppm, and A. rubrum were grown in growth chambers at CO_2 concentrations of 422 or 722 ppm. Both species were grown from seed. The elevated CO_2 treatment was crossed with two water table treatments, flooded and non-flooded.