大气CO_(2)浓度升高对黄河三角洲湿地盐地碱蓬和互花米草光合特性的影响  

Impacts of elevated atmospheric CO_(2)concentration on the photosynthetic characteristics of Suaeda salsa and Spartina alterniflora in the Yellow River Delta wetland

作　　者：张鑫 袁俊吉 彭思利 刘德燕 丁维新[2] Zhang Xin;Yuan Junji;Peng Sili;Liu Deyan;Ding Weixin(Co-Innovation Center for Sustainable Forestry in Southern China,College of Ecology and Environment,Nanjing Forestry University,Nanjing 210037,Jiangsu,P.R.China;State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,Jiangsu,P.R.China)

机构地区：[1]南方现代林业协同创新中心,南京林业大学生态与环境学院,江苏南京210037 [2]中国科学院南京土壤研究所,土壤与农业可持续发展国家重点实验室,江苏南京210008

出　　处：《湿地科学》2025年第1期160-168,共9页Wetland Science

基　　金：江苏省碳达峰碳中和科技创新专项资金项目(BK20220020);江苏省杰出青年基金项目(BK20230050);国家自然科学基金项目(42177301,U1906220)资助。

摘　　要：明确湿地植物光合作用对大气CO_(2)浓度升高的响应特征,有助于科学预测未来气候变化对湿地生态系统结构和功能的影响。选择黄河三角洲滨海湿地C3植物盐地碱蓬(Suaeda salsa)和C4植物互花米草(Spartina alterniflora)为研究对象,在开顶箱CO_(2)熏气系统中设置2种CO_(2)浓度(常规和+400μmol/mol),利用Li‒6800便携式光合系统测定植物的净光合速率、气孔导度、蒸腾速率以及光响应曲线和CO_(2)响应曲线,研究两种湿地植物在大气CO_(2)浓度升高情景下的光合‒光响应特性差异。结果表明,CO_(2)浓度升高对C3植物盐地碱蓬光合作用的促进作用大于C4植物互花米草,但两种CO_(2)浓度下盐地碱蓬的净光合速率均显著低于互花米草;CO_(2)浓度升高对两种植物光响应曲线参数有显著影响,且盐地碱蓬最大净光合速率对CO_(2)浓度升高的响应强度大于互花米草;CO_(2)浓度升高后,盐地碱蓬CO_(2)响应曲线转折点后移,互花米草的CO_(2)响应曲线走势变化不大;CO_(2)浓度升高降低了互花米草的气孔导度和蒸腾速率,但对盐地碱蓬的影响不显著,蒸腾速率的变化趋势与气孔导度的变化类似。综上,CO_(2)浓度升高对两种植物的光合特性产生了显著影响,但盐地碱蓬适应CO_(2)浓度升高的能力更强,本研究对于评估CO_(2)浓度升高对湿地碳循环的影响具有一定的参考意义。A comprehensive understanding of the photosynthetic response of wetland plants to increased atmospheric CO_(2)concentrations is crucial for predicting the effects of future climate change on the structure and function of wetland ecosystems.This study used the open top chamber systems(OTCs)to simulate two CO_(2)concentrations(ambient and+400μmol/mol)in coastal wetlands of the Yellow River Delta.The intact soil columns(100 cm height and 40 cm diameter),along with C3(Suaeda salsa)and C4(Spartina alterniflora)plants,were extracted from wetland using stainless steel barrel and transferred into the OTCs.To investigate the impacts of elevated atmospheric CO_(2)concentrations on the photosynthetic characteristics of the two wetland plants,the Li-6800 portable photosynthesis system was employed to measure the net photosynthesis rate,stomatal conductance,transpiration rate,light and CO_(2)response curves.Although elevated CO_(2)concentrations exerted a stronger stimulatory effect on photosynthetic activity in the C3 plant S.salsa compared to the C4 plant S.alterniflora,the net photosynthetic rate of S.salsa remained significantly lower than that of S.alterniflora under both ambient and elevated CO_(2)conditions.The elevated CO_(2)concentration significantly impacted the parameters of the light response curves for both plants.The maximum net photosynthetic rate of S.salsa displayed a more robust response to the increased CO_(2)concentration compared to S.alterniflora.Compared to ambient CO_(2)levels,the turning point of CO_(2)response curve for S.salsa under elevated CO_(2)shifted backward,while that of S.alterniflora showed little change.Notably,elevated CO_(2)led to a decrease in stomatal conductance and transpiration rate in S.alterniflora,but not for S.salsa.Overall,elevated CO_(2)concentration significantly influenced the photosynthetic traits of both plant species,with S.salsa demonstrating a greater capacity to adapt to elevated CO_(2)concentrations.This research provided insights for evaluating the effects of incre

关 键 词：全球变化 CO_(2)浓度升高 光合特性 互花米草 盐地碱蓬 

分 类 号：X173[环境科学与工程—环境科学] Q948[生物学—植物学]