Under elevated CO2 most plant species show higher rates of photosynthesis, increased growth, decreased water use and lowered tissue concentrations of nitrogen and protein. (judithcurry.com)
Not well, according to this paper: when top and bottom leaves are placed in the same low light, the lower canopy leaves showed lower rates of photosynthesis. (sciencedaily.com)
New research shows that the global rate of photosynthesis is 25 % faster than was previously thought, possibly affecting models of global climate change. (earthtimes.org)