| Abstract: | Eighty-four published papers were synthesized using meta-analysis (a statistical method to summarize the different individual studies under the same subject), with results of the environmental factors (soil water deficit, low soil nitrogen, high temperature and high concentration O3) affecting significantly the response of plant to elevated atmospheric CO2 concentrations. Under unstressed condition, the overall effect sizes of twelve ecophysiological variables of C3 plants were negative, other twelve positive. For negative effect group, the first five variables ranked as: stomatal conductance ( g s)> leaf dark respiration rate （Rd）>leaf nitrogen content on a mass basis ( N m)>leaf protein content on a mass basis ( Prm)>leaf nitrogen content on a structural mass basis ( Ns); for positive one, root biomass ( Bt)>shoot biomass ( Bs)>leaf starch content on a mass basis ( St )>light saturated net photosynthetic rate ( A )>total biomass ( Bt). The Bt and A of C3 plants increased 30.01% and 40.36% respectively under unstressed condition, while g s decreased 30.39%. |
