| 摘要: |
| 在长江南通市区段国控断面( 李港对照断面) 上自1996—1999 年每两个月定期采样, 测定悬浮颗粒物的碳、氮同位素及其相关参数。研究发现: 稳定碳同位素值分布区域在-23.6‰— -27.1‰之间; 稳定氮同位素多分布在1.4‰—5.9‰。两者的季节变化趋势与陆源输入和现场浮游植物的组成和生长状况有关。δ15N 、C/N 比值均不能严格体现物源影响,受到水体中有机质的转化和微生物活动的影响而被改造。借助简单模式, 获得估算的陆源贡献随季节变化的规律, 并证实在1998 年夏长江南通的陆源输入有明显的增大, 与1998 年长江大洪水事件吻合。 |
| 关键词: 碳同位素, 氮同位素, 悬浮颗粒物, 长江 |
| DOI： |
| 分类号: |
| 基金项目:国家重点基础研究专项经费资助项目, G1999043705 号; 国家杰出青年科学基金, 49525609 号; 国家自然科学基金, 40006008 号 |
附件 |
|
| SEASONAL VARIABILITY OF STABLE CARBON AND NITROGEN ISOTOPE OF SUSPENDED PARTICULATE MATTER IN THE CHANGJIANG RIVER |
|
WU Ying1, ZHANG Jing1, ZHANG Zai-Feng2, REN Jing-Ling3, CAO Jian-Ping4
|
|
1.State Key Laboratory of Estuarine and Coastal Research , East China Normal University;2.Institute of Environmental Protection of Nantong;3.College of Chemistry and Chemical Engineering, Ocean University of Qingdao;4.The Key Laboratory of Industrial Biotechnology , Ministry of Education
|
| Abstract: |
| Samples of suspended particulate matter were collected along the Nantong section, the Changjiang River, every two months during 1996—1999. Stable carbon and nitrogen isotopes and elemental C/N ratios were studied for source tracing of particulate organic matter. The δ13C and δ15N compositions of SPM from the section varied from - 23.6‰ to - 27.1‰ and 1.4‰ to 5.9‰, respectively. There were no significant differences in the δ13C and δ15N compositions between the sampling sites. The seasonal variation reflected the control of terrigenous inputs and in situ primarily production. δ15N and C/ N ratio could provide limited information on the source because the original POM source signature may be lost or overprinted by biochemical alteration. Only δ13C ratios are reliable and a simple model of δ13C is used to estimate the proportions of terrigenous contribution for different seasons. Compared with the data published in literature, the δ15N composition of SPM in the Changjiang River is comparable with other estuaries. A simple model is used to estimate the contribution and variation of terrigenous organic matter inputs for the study area. Higher terrestrial inputs were observed in the summer of 1998, in response to a major flood event which occurred during that period of time. |
| Key words: Stable carbon/nitrogen isotopes, Suspended particulate matter, Temporal variability, Changjiang River |
