CO2浓度倍增对湿地小叶章生理特性的影响

选择三江平原湿地典型草甸化小叶章（Calamagrostis angustifolia）为研究对象，利用开顶箱控制CO₂浓度，模拟CO₂浓度倍增对小叶章生理特性的影响. 结果表明，小叶章对CO₂浓度倍增的响应依赖于氮素供应状况. 缺氮 （0 kg/hm2） 条件下，CO₂浓度倍增使w（叶绿素），w（游离氨基酸）和w（可溶性蛋白质）降低，w（可溶性糖）增加;而当氮素供应充足时，w（叶绿素），w（游离氨基酸）和w（可溶性蛋白质）均显著增加. 施氮促进小叶章叶绿素、游离氨基酸和可溶性蛋白质合成，降低了w（可溶性糖）. 小叶章在高浓度（以摩擦尔分数计）CO₂（700 μmol/mol）熏蒸40 d，光合能力出现下降趋势. 施氮可以促进小叶章的生长，调节其对CO₂浓度升高的适应现象. 

Effects of CO2 Concentration Doubling on Physiological Characteristics of Calamagrostis angustifolia in Freshwater Marsh

The freshwater marsh predominated with Calamagrostis angustifolia in Sanjiang Plain was studied. Open top chamber was used in the controlling of CO2 concentration in order to model the impacts of CO₂ concentration doubling on the physiological characteristics of Calamagrostis angustifolia. The results showed that the response of Calamagrostis angustifolia to CO₂ concentration doubling was strongly dependent on nitrogen supply. Doubled CO₂ concentration induced a decrease of w（chlorophyll）, w（free amino acid） and w（soluble protein） under nitrogen deficit conditions （0 kg/hm2）. The w（chlorophyll）, w（free amino acid） and w（soluble protein） was significant enhanced when the supply of nitrogen was ample.Nitrogen fertilization increased the content of chlorophyll, free amino acid and soluble protein while decreased the content of soluble sugar. After 40 days of CO₂ concentration doubling treatment, the photosynthesis of Calamagrostis angustifolia began to decline. Nitrogen addition can enhance the growth of Calamagrostis angustifolia, through which the acclimation to high-concentration CO₂ （700 μmol/mol） would be adjusted.