| 摘要: |
| 于2004年10月采集南黄海4个站位的柱状沉积物和29个站位的表层沉积物，用氧化浸取分光光度法研究了自然粒度下沉积物中的氮、磷分布特征以及控制其分布的生物地球化学机制。结果表明，多数站位随着沉积深度的增加，沉积物中氮、磷浓度趋于稳定。4个站稳定时氮浓度平均约为289μg/g，磷约为329μg/g，平均稳定浓度出现的沉积层次分别为氮>30cm，磷>22cm。氮、磷垂直分布形状的规则性与沉积速率密切相关，沉积速率越小的站位，其氮、磷垂直分布愈规则;海洋沉积物中的氮主要来源自海洋生物的代谢，而磷与陆源碎屑输入密切相关。氮与沉积物粘土含量、浮游动物生物量干重有明显的正相关关系。海水中浮游动物干重每增加1mg/m3，则沉积物中氮浓度增加5.64μmol/g，磷不存在这样的关系。沉积物中氮的早期成岩速率远高于磷，在沉积物海水界面附近氮约为磷的7.4倍。海水浮游生物生物量与沉积物中氮的早期成岩类型密切相关，在所研究的2004年秋季海水中，浮游动物生物量干重19mg/m3是沉积物中氮早期成岩类型转变的界限值，小于这一界限值，水体中的氮趋向于向沉积物中凝聚;大于19mg/m3，则沉积物中的氮趋向于向水体释放。 |
| 关键词: 生物地球化学过程 氮与磷 沉积物 南黄海 |
| DOI： |
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| 基金项目:中国科学院创新重大项目,KZCX1SW0108号;中国科学院“百人计划”资助项目,科人2003202号;青岛市科技将才专项计划项目,043JJ03号和052JC90 |
附件 |
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| BIOGEOCHEMICAL CHARACTERISTICS OF NITROGEN AND PHOSPHORUS IN THE SOUTH YELLOW SEA SEDIMENTS |
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SONG Jin-Ming1, LI Xue-Gang1, SHAO Jun-Bo2, HE Zhi-Peng1,3, ZHANG Nai-Xing1,3
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1.Institute of Oceanology,Chinese Academy of Sciences,Qingdao,266071;2.Zhoushan Marine Eco-environmental Monitoring Station of Zhejiang Province,Zhoushan,316004;3.The Graduate School,Chinese Academy of Sciences,Beijing,100039
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| Abstract: |
| The distributions of nitrogen (N) and phosphorus (P) in sediment cores in the south Yellow Sea (SYS) were studied in detail in this paper. The core sediments from 4 stations and surface sediments from 29 stations were collected in SYS in October 2004. The peak concentrations of N and P in the sediments, occurred in depth of 5–35 cm, and the phosphorus peak was close to the sediment-seawater interface. The concentrations gradually approach to constants with the depth increasing. The average constant concentrations were 289 and 329 μg/g for N and P in depth of > 30 cm and > 22 cm, respectively. The vertical patterns of N and P distribution were closely related to the sedimentation rate in a regular pattern at the stations with low sedimentation rate. The N content in sediment was mainly from the metabolism of marine organisms, while that of P was mainly from input of terrestrial detritus. The ratio of N/P was controlled by N distribution in the sediments of SYS. A clear positive correlation has been revealed among N concentration, clay amount in the sediment and dry weight of zooplankton biomass. For every 1 mg/m3 increased in dry weight, the N concentration would add 5.64 μmol/g up; however, no such relation has been found for P. Early diagenesis rate of N was much higher than that of P, e.g. the rate of N was 7.4 times greater than that of P in sediments. The critical value of early diagenesis for N was 19 mg/m3 calculated from the data of autumn 2004. In other words, below the value, N in seawater would incline to accumulate in sediments; while above the threshold, N would be released from sediment to seawater. |
| Key words: Biogeochemical process, Nitrogen and phosphorus, Sediments, The South Yellow Sea (SYS) |
