The net CO2 assimilation rate, stomatal conductance, RuBPcase (ribulose 1,5-biphosphate carboxylose) activity, dry weight of aboveground and belowgroud part, plant height, the length and diameter of taproot ofPinus ko...The net CO2 assimilation rate, stomatal conductance, RuBPcase (ribulose 1,5-biphosphate carboxylose) activity, dry weight of aboveground and belowgroud part, plant height, the length and diameter of taproot ofPinus koraiensis seedlings were measured and analyzed after six-week exposure to elevated CO2 in an open-top chamber in Changbai Mountain of China from May to Oct. 1999. Seedlings were planted in four different conditions: on an open site, control chamber, 500 μL·L?1 and 700 μL·L?1 CO2 chambers. The results showed that the total biomass of the seedlings increased whereas stomatal conductance decreased. The physiological responses and growth to 500 μL·L?1 and 700 μL·L?1 CO2 varied greatly. The acclimation of photosynthesis was downward to 700 μL·L?1 CO2 but upward to 500 μL·L?1 CO2. The RuBPcase activity, chlorophyll and soluble sugar contents of the seedlings grown at 500 μL·L?1 CO2 were higher than that at 700 μL·L?1 CO2. The concentration 500 μL·L?1 CO2 enhanced the growth of aboveground part whereas 700 μL·L?1 CO2 allocated more carbon to belowground part. Elevated CO2 changed the carbon distribution pattern. The ecophysiological responses were significantly different between plants grown under 500 μL·L?1 CO2 and 700 μL·L?1 CO2.展开更多
文摘The net CO2 assimilation rate, stomatal conductance, RuBPcase (ribulose 1,5-biphosphate carboxylose) activity, dry weight of aboveground and belowgroud part, plant height, the length and diameter of taproot ofPinus koraiensis seedlings were measured and analyzed after six-week exposure to elevated CO2 in an open-top chamber in Changbai Mountain of China from May to Oct. 1999. Seedlings were planted in four different conditions: on an open site, control chamber, 500 μL·L?1 and 700 μL·L?1 CO2 chambers. The results showed that the total biomass of the seedlings increased whereas stomatal conductance decreased. The physiological responses and growth to 500 μL·L?1 and 700 μL·L?1 CO2 varied greatly. The acclimation of photosynthesis was downward to 700 μL·L?1 CO2 but upward to 500 μL·L?1 CO2. The RuBPcase activity, chlorophyll and soluble sugar contents of the seedlings grown at 500 μL·L?1 CO2 were higher than that at 700 μL·L?1 CO2. The concentration 500 μL·L?1 CO2 enhanced the growth of aboveground part whereas 700 μL·L?1 CO2 allocated more carbon to belowground part. Elevated CO2 changed the carbon distribution pattern. The ecophysiological responses were significantly different between plants grown under 500 μL·L?1 CO2 and 700 μL·L?1 CO2.
