摘要
以陕西省榆林市海流兔河流域上游区域为研究对象,通过结合河流与土壤CO_(2)浓度高频监测技术与频谱分析方法,剖析河流-土壤横断面CO_(2)动态模式及其影响因素与演化过程.基于研究剖面上4个监测点的CO_(2)浓度时间序列,分离出周期为0.5与1d的强烈昼夜信号,推断出河流内部的昼夜生物代谢过程是控制CO_(2)浓度变化的关键因素.流域内降水等事件引起的水文条件变化会引起CO_(2)逸散,对水体碳循环过程产生显著影响.根据相关性分析,判断河流与土壤CO_(2)动态的主要影响因子为温度与土壤含水量,并证实了土壤为河流CO_(2)的主要来源,地下水是实现土壤与河流间的碳迁移过程的重要媒介.
With the objective to characterize CO_(2) dynamics from soil to streams,and to identify relevant influential factors along with temporal evolution patterns,this study established a high-frequency CO_(2) concentration monitoring transect with four measuring points in a stream and adjacent soil located in the upper reach of the Hailiutu River Basin in Yulin city,Shannxi province.With the spectrum and wavelet analysis,strong diurnal signals with periods of 0.5 and 1d frequencies are identified based on the CO_(2) concentration time series,indicating that the diurnal stream metabolism plays a key role in regulating in-stream CO_(2) dynamics.Additionally,variations in hydrological events,i.e.precipitation in the catchment,may lead to prominent changes in CO_(2) evasion,which has a significant impact on the carbon cycling between stream and soil.Bivariate wavelet coherence analysis reveals that temperature and soil water content directly control stream and soil CO_(2) dynamics,and confirms that soil-stored CO_(2) is the main source of the stream CO_(2) evasion.Further,the results indicate that groundwater is an important pathway for carbon transport from soil to streams.
作者
李家琪
姜振蛟
戴鑫
汪钏
武丽文
谢月清
LI Jia-qi;JIANG Zhen-jiao;DAI Xin;WANG Chuan;WU Li-wen;XIE Yue-qing(School of Earth Sciences and Engineering,Nanjing University,Nanjing 210023,China;Frontiers Science Center for Critical Earth Material Cycling,Nanjing University,Nanjing 210023,China;College of New Energy and Environment,Jilin University,Changchun 130026,China;The Department of Health and Environmental Sciences,Xi’an Jiaotong-Liverpool University,Suzhou 215123,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第12期6667-6676,共10页
China Environmental Science
基金
国家自然科学基金资助项目(41972246,41807185)
关键地球物质循环前沿科学中心“科技人才团队”项目,中央高校基本科研业务费专项资金(020614380135)。
