长江口表层沉积物中生源硅的时空分布与影响因素  

Seasonal variations and its controlling factors of biogenic silica in surface sediment of the Yangtze River estuary

作　　者：张珊珊 线薇薇[1,2,4] 梁翠 牟京龙[1,2,3] ZHANG Shanshan;XIAN Weiwei;LIANG Cui;MU Jinglong(Key Laboratory of Marine Ecology&Environmental Science,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,Shandong,China;Marine Ecology&Environmental Science Functional Laboratory,Pilot National Laboratory for Marine Science and Technology,Qingdao 266237,Shandong,China;University of Chinese Academy of Sciences,Beijing 100049,China;Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,Shandong,China)

机构地区：[1]中国科学院海洋研究所海洋生态与环境科学重点实验室,山东青岛266071 [2]青岛海洋科学与技术试点国家实验室海洋生态与环境科学功能实验室,山东青岛266237 [3]中国科学院大学,北京100049 [4]中国科学院海洋大科学研究中心,山东青岛266071

出　　处：《水利水电技术（中英文）》2022年第S01期61-67,共7页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(31872568);三峡工程运行安全综合监测系统:库区维护和管理(2136703)

摘　　要：为了解长江口及其邻近海域表层沉积物中生源硅(BSi)的时空变化特征及其与影响因素的关系,依据2014年长江口冬季(2月)、春季(5月)、夏季(8月)和秋季(11月)综合调查数据,测定分析了沉积物中BSi、有机质和粒度等指标。结果表明:长江口及其邻近海域表层沉积物BSi浓度范围是0.045%~0.650%,均值为0.327%;BSi浓度存在显著的时空变化差异:秋季含量最高,夏季和冬季次之,春季最低;不同季节BSi空间分布也存在显著差异,春、夏季呈“北高、南低”的变化趋势,秋、冬季则表现为“南高、北低”的分布特征。Pearson相关性分析结果显示,影响BSi时空分布的因素存在季节差异:春季,BSi与Chl.a之间存在显著正相关,反映了该季主要是底栖硅藻等初级生产者对沉积物中BSi的贡献较大;夏季,BSi除受初级生产的贡献外,还与沉积物中有机碳、氮(TOC、TN)的优先分解而被积累保存相关;秋季,TOC和TN含量及沉积物粒径是影响BSi的重要因素;冬季BSi分布影响因素较为复杂,与沉积物理化性质呈极显著相关性。研究结果揭示,富含有机碳的细颗粒物质富集及底栖硅藻的初级生产是长江口生源硅积累的主要受控因素。In order to understand the seasonal variation characteristics and its controlling factors of biogenic silica(BSi)in surface sediments of the Yangtze River estuary and its adjacent areas,the concentrations of BSi,organic matter,and grain size in sediments are determined and analyzed.Four cruises are carried out in winter(February),spring(May),summer(August)and autumn(November)in 2014.The results show that the concentrations of BSi ranged from 0.045%to 0.650%,with an average of 0.327%.There are significant temporal and spatial differences in BSi concentration,with the highest content occurring in autumn,followed by summer and winter,and the lowest content in spring.Meanwhile,the distribution of BSi appeared an obvious seasonal differences.In spring and summer,high BSi content is found in the north areas and low in the south areas,while in autumn and winter the trend are reversed.Pearson correlation analysis results show that the factors controlling the seasonal variations of BSi varied greatly.In spring,the significant positive correlation between BSi and chlorophyll a(Chl.a)reflected that the primary producers,such as benthic diatoms,contributed much more to the BSi.In summer,in addition to the contribution of primary production,BSi is accumulated due to the preferential decomposition of total organic carbon(TOC)and total nitrogen(TN)in sediments.In autumn,the contents of TOC and TN and the grain size of sediments are important factors affecting the distribution of BSi.However,the controlling factors in winter are more complicated,which are extremely significant correlated with the physical and chemical properties of sediments.The study revealed that the enrichment of fine particulate matter in organic carbon and the primary production of benthic diatoms are the main reasons for the accumulation of BSi.

关 键 词：生源硅 表层沉积物 季节变化 影响因素 长江口 

分 类 号：X52[环境科学与工程—环境工程]