Ecophysiological response of Pinus koraiensis seedlings to elevated CO2

Studies on the ecophysiological response of Pinus koraiensis seedlings were conducted in open-top chambers which were controlled with CO2 concentration of about 500 and 700 mumol.mol-1. The result shows that there were different responses in net photosynthetic rate and stomatal conductance at high CO2(500 and 700 mumol.mol-1) and ambient CO2 concentrations. Under 500 mumol.mol-1 CO2, the carboxylase activity of RuBP was the highest, the photosynthesis showed "up-ward", the average daily net CO2 assimilation was the greatest, and the contents of chlorophyll and soluble sugars were the highest. While under 700 mumol.mol-1 CO2, the photosynthesis showed "down-ward" and was lower than that of the control, and the enzyme activity and the contents of substances were the lowest.