通过对28种园林植物在不同CO2浓度水平下的气体交换参数的观测,分析了净光合速率、气孔导度、蒸腾速率和水分利用效率等生理生态指标的变化趋势与规律。结果表明,所测植物净光合速率和水分利用效率随CO₂浓度升高而线性增加,但不同植物种类对高CO₂浓度的反应存在较大差异。气孔导度和蒸腾速率与CO₂浓度呈线性负相关关系。当CO₂浓度倍增(350~700μmol·mol^-1)时,28种园林植物净光合速率平均提高31.2%,气孔导度降低16.5%,蒸腾速率下降11.7%,而水分利用效率则提高了49.2%。不同光合途径的植物净光合速率和水分利用效率受CO₂浓度增加的影响程度为:C₃植物较大,C₄植物较小,CAM植物介于两者之间。对不同生活型植物而言,影响程度则为草本C₃植物较大,乔木C₃植物较小,灌木C₃植物居于两者之间。

Based on analysis of net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) and water use efficiency (WUE), ecophysiological responses of 28 species of garden plants to CO₂ enrichment were compared. The results showed that Pn and WUE were positive and Gs, Tr negative linearly correlated with a series of CO₂ concentrations over 350 μmol·mol^-1.The average Pn and WUE increased by 31.2% and 49.2%, the average Gs and Tr decreased by16.5% and 11.7% at doubled CO₂ level from 350 to 700μmol·mol^-1.The order of Pn and WUE from high to low was C₃plant, CAM plant, C₄ plant with CO₂ concentration increasing.