摘要
长江、黄河、珠江和黑龙江是我国的4条主要大型河流,其淡水和陆源物质的输送对边缘海的物理、生物和地球化学过程具有重要影响。通过碳同位素(13C和14C)与浓度相结合的方法,研究了4条河流输送陆源有机碳(POC和DOC)和无机碳(PIC和DIC)的同位素特征和通量,通过同位素端元模型对各河流输送陆源有机和无机碳的来源做了定量计算并与世界主要河流进行了比较。长江、黄河和珠江输送的DIC和DOC具有千年尺度的14C年龄,高于世界其他大河流,主要受岩石风化以及人类活动的影响。黑龙江流域输送的DIC、DOC及POC具有相对年轻的14C年龄,这表明其河流碳组分主要受陆源植被有机质降解影响。该研究对认识我国主要河流输送陆源碳的特征、来源和控制因素及对边缘海碳循环的影响具有实质意义。
The Changjiang,Huanghe,Zhujiang and Heilongjiang are the four largest rivers in China and they transport large amount of fresh water and terrigenous materials,including both inorganic and organic carbon into the ocean.The sources of the terrestrial carbon transported in the four rivers,however,have not been well constrained and compared.In this study,we used carbon isotopes(13C and 14C)combined with concentration measurements to investigate and compare the sources and fluxes of Dissolved Inorganic Carbon(DIC),Particulate Inorganic Carbon(PIC),Dissolved Organic Carbon(DOC)and Particulate Organic Carbon(POC)in the four rivers.The contributions of the potential sources to both DIC and DOC were quantitatively calculated using a dual isotope and three end member model.The results showed that the concentrations and isotope characteristics of the carbon pools in the river depended largely on the geological setting,surrounding environment and the anthropogenic influence of the drainage basins.Compared with other large rivers in the world,the concentrations of DIC in the Changjiang,Huanghe and Zhujiang were higher,but the DIC fluxes in the Huanghe and Zhujiang were lower.The DOC concentrations in the Heilongjiang River were higher and lower in the other three rivers compared with the average value of the world largest 25 rivers.The Changjiang,Huanghe and Zhujiang all transport millennia aged carbon.The old riverine DIC reflects the influence of chemical weathering of carbonate rocks and the old DOC reflects influence mainly from pre-aged soil OC.These ancient terrestrial carbon discharged by the rivers could have significant effects on the carbon cycle and ecosystems in the China’s marginal seas.
作者
单森
齐远志
罗春乐
付文静
薛跃君
王旭晨
Shan Sen;Qi Yuanzhi;Luo Chunle;Fu Wenjing;Xue Yuejun;Wang Xuchen(Key Laboratory of Marine Chemistry Theory and Technology/Center for Frontier Science of Deep Ocean and Earth System,Ocean University of China,Qingdao 266100,China;Center for Isotope Geochemistry and Geochronology,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266237,China)
出处
《地球科学进展》
CAS
CSCD
北大核心
2020年第9期948-961,共14页
Advances in Earth Science
基金
国家自然科学基金项目“重新评估河流输入陆源有机碳对海洋碳循环的贡献和影响”(编号:41776082)
中央高校基本科研业务费专项“C3、C4植物生物降解对水体和沉积物间隙水溶解无机碳同位素值的影响”(编号:201861017)资助。
关键词
河流
有机碳
无机碳
碳通量
碳同位素
Rivers
Organic carbon
Inorganic carbon
Carbon flux
Carbon isotope
