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涡度相关系统观测高度以下的CO2储存通量对准确评价森林生态系统与大气间净CO2交换量(NEE)有着重要的影响.本研究以长白山阔叶红松林为研究对象,利用2003年的涡度相关观测数据以及CO2浓度廓线数据,分析了CO2储存通量的变化规律及其对碳收支过程的影响.结果表明:涡度相关观测高度以下的CO2储存通量具有典型的日变化特征,其最大变化量出现在大气稳定与不稳定层结转换期.利用涡度相关系统观测的单点CO2浓度变化方法与利用CO2浓度廓线方法计算的CO2储存通量差异不显著.忽略CO2储存通量,在半小时尺度上会造成对夜间和白天的NEE分别低估25%和19%,在日和年尺度上,会对NEE低估10%和25%;忽略CO2储存通量,会低估Michaelis-Menten光响应方程及Lloyd-Taylor呼吸方程的参数,并且对表观初始量子效率α和参考呼吸Rref的低估最大;忽略CO2储存通量,在半小时、日及年尺度上,均会对总光合作用(GPP)和生态系统呼吸(Re)低估约20%.
The CO2 storage flux below the observed height of the eddy covariance system has an important impact on the accurate assessment of net CO2 exchange (NEE) between the forest ecosystem and the atmosphere.In this study, the broadleaved Korean pine forest in Changbai Mountain was used as the research object, Degree correlation observation data and CO2 concentration profile data, the variation regularity of CO2 storage flux and its influence on carbon budget are analyzed.The results show that CO2 fluxes below the vorticity-related observation height have typical diurnal variation characteristics , The maximum variation appeared in the period of atmospheric stability and unstable stratification.There was no significant difference between the single point CO2 concentration observed by the eddy covariance system and the CO2 flux calculated by CO2 concentration profile.The CO2 storage Fluxes will cause an estimated 25% and 19% NEE to be underestimated for night and day at half-hour scale and 10% and 25% to NEE on day and year scale, respectively; neglect of CO2 storage will underestimate Michaelis -Menten light response equation and Lloyd-Taylor breathing equation parameters, and the apparent initial quantum efficiency α and reference respiratory Rref underestimated the maximum; ignore CO2 storage flux in the half hour, day and year scales, will be Total photosynthesis (GPP) and ecosystem respiration (Re) from about 20% undervalued.