CO2升高对红松幼苗水分生理特征与土壤含水率变化的影响

采用生长箱培养法,分别研究700与350 μmol/mol CO2浓度下红松幼苗水分生理特征和土壤含水率变化。研究表明:1)初始土壤含水率相同,相同条件培养5 d后高浓度CO2培养苗木土壤含水率较高;2)土壤含水率没有显著差异时,高浓度CO2培养导致苗木气孔导度、蒸腾速率和地上部含水率下降,水分利用效率和叶水势升高;3)随着土壤含水率产生差异,高浓度CO2培养苗木的气孔导度、蒸腾速率、水分利用效率和叶水势没有发生显著变化,而低浓度CO2培养苗木的气孔导度、蒸腾速率下降,水分利用效率与叶水势升高不显著。 

Effects of elevated CO2 on physiological characteristics of water in Pinus koraiensis seedlings and soil moisture in a controlled environment

We used growth chamber incubation to investigate the physiological characteristics of water in the soil of Pinus koraiensis seedlings at two levels of CO2, i.e. at 700 and 350 μmol/mol. The results revealed the following: 1) Starting from the same initial level of soil moisture, at the higher CO2 concentration, the soil moisture was higher after five days under similar growing conditions. 2) An elevated CO2 level resulted in a decrease of stomatal conductance, in the rate of transpiration and in the amount of water in the aboveground parts of the seedlings, but led to an increase in water use efficiency and leaf water potential, while soil moisture did not differ greatly in the two CO2 treatments. 3) While soil moisture differed in the two CO2 treatments, at 700 μmol/mol CO2 there were no significant changes in stomatal conductance, the rate of transpiration, water use efficiency and leaf water potential. At 350 μmol/mol CO2 stomatal conductance and the rate of transpiration decreased, while the increases in water use efficiency and leaf water potential were not significant.