夏季南黄海海域颗粒有机物和浮游生物的碳、氮稳定同位素分析

发布时间：2018-02-09 17:59

本文关键词： 颗粒有机物浮游生物碳氮稳定同位素长江冲淡水黄海冷水团　出处：《中国海洋大学》2015年硕士论文　论文类型：学位论文

【摘要】：海洋生态系统中有机物的来源及分布是海洋生态系统食物网研究中的重要内容,稳定同位素的方法是此领域近年来新兴的研究方法。碳、氮稳定同位素的分馏作用发生在有机物生物地球化学过程中,可以揭示有机物的来源、消费者的食物组成以及各生物在食物网中所处的营养级,已广泛应用于全球生物地球化学研究中,为海洋生态系统的研究提供了非常有价值的信息。本研究通过分析2013年夏季南黄海123。E和124。E断面上所采集的颗粒有机物及浮游生物碳、氮稳定同位素的组成,探讨了夏季南黄海研究海域的主要水文特征(黄海冷水团和长江冲淡水)对水体中颗粒有机物及浮游生物碳、氮稳定同位素空间分布的影响;并通过水体中颗粒有机物碳、氮稳定同位素组成的差异分析水体中颗粒有机碳、氮的来源,以揭示南黄海海域生态系统的特征以及物质的输送与传递特征。获得的主要结果与结论如下：(1)对123。E和124。E断面上颗粒有机物碳、氮含量及其稳定同位素组成的空间分布情况表明,夏季研究区域不同水层的颗粒有机物主要受初级生产过程、沉积物再悬浮作用、有机物的分解和矿化作用以及生物的同化吸收作用的影响。(2)南部水域,长江冲淡水主要对33.5。N以南区域的表层水体产生影响。对比不同水层之间颗粒有机物δ13CPOC的差异性,可以发现水体中不同水层颗粒有机碳的来源不同。表层水体中颗粒有机碳来源为海洋浮游植物,而其他水层的颗粒有机碳则主要来自于底层沉积物的再悬浮作用；分析颗粒有机物δ15NPN,结果表明上层水体中的颗粒氮主要受生物同化吸收作用的影响；下层水体中颗粒氮则主要由含氮有机物的矿化分解产生。(3)黄海冷水团的主要影响范围是北部研究水域的下层水体。比较黄海冷水团水域不同水层之间颗粒有机物δ13CPOC的差异性,发现黄海冷水团水域垂直方向上颗粒有机碳的组成不同,30 m水深以上的水体的颗粒有机碳来自海洋自身产生的有机碎屑(浮游生物及其排泄物和残骸),而底层水体的颗粒有机碳则为底层沉积物再悬浮产生的有机物及其分解产物。与南部水域底层水体颗粒有机物δ13CPOC之间存在的显著性差异(p0.01),一定程度上反映了陆源物质的运移,南部水域沉积物主要为长江物质,而冷水团水域表层沉积物主要为黄河物质。水体中颗粒有机物δ15NPN值随水深的增加而降低,其来源主要为有机物的分解和矿化。(4)不同浮游生物网所采集浮游生物的碳、氮稳定同位素分布规律表明,初级生产过程和浮游动物丰度是影响其分布的两个因素。小型浮游生物网所采集的浮游植物δ13C值随浮游植物丰度的增大而升高；而大、中型浮游生物网所采集的浮游动物δ13C随浮游动物丰度增大而升高。比较三种浮游生物网采集浮游生物δ15N值,表明三种网所采浮游生物均包含浮游植物和浮游动物,其中小型浮游生物网采集的浮游植物比重较大,而大型浮游生物网采集的浮游动物所占比重较大。
[Abstract]:The source and distribution of organic matter in marine ecosystems is an important content in the study of marine ecosystem food webs and method of stable isotopes is a new research methods in this field in recent years. Carbon and nitrogen stable isotope fractionation occurred in the organic biogeochemistry process, sources can reveal the organic food consumers. The composition and the organisms in the food web nutrition level, has been widely used in global biogeochemical studies, provide valuable information for the study of marine ecological system. Through the analysis of particulate organic carbon and plankton collected in South Yellow Sea in summer 2013 123.E and 124.E section, composed of stable nitrogen isotope, discusses the main hydrological characteristics in the Southern Yellow Sea in summer in the study area (the Yellow Sea cold water mass and the Changjiang River) of water in particulate organic matter and plankton carbon Effect of nitrogen isotope space, stable distribution; and through the water in particulate organic carbon, different nitrogen stable isotope composition analysis of particulate organic carbon in water, nitrogen sources, in order to reveal the characteristics of conveying and transfer characteristics of the South Yellow Sea ecosystem as well as the material. The main results and conclusions are as follows: (1) to 123.E section 124.E and particulate organic carbon, showed that the spatial distribution of nitrogen content and stable isotopic compositions of particulate organic matter, the area in different water layers is mainly affected by the primary production processes, sediment resuspension, the influence of organic matter decomposition and mineralization and biological assimilation effect. (2) the southern waters. The Changjiang River is mainly the 33.5.N effect to the south area of the surface water. The difference between different layers of particulate organic matter in Delta 13CPOC, can be found in different layers of particles in water The source of organic carbon in surface waters. Different particulate organic carbon source for phytoplankton, particulate organic carbon and other aquifers are mainly from the bottom sediment resuspension; analysis of particulate organic matter in Delta 15NPN, the result shows that the influence of particulate nitrogen in the upper water column is mainly affected by the biological effects of particulate nitrogen assimilation; lower water it is mainly composed of organic compounds containing nitrogen mineralization. (3) the main influence range of the Yellow Sea cold water mass in the north of the waters of the bottom water. The differences between the different layers of water of the Yellow Sea cold water mass of particulate organic matter in Delta 13CPOC, found that the vertical direction of the Yellow Sea cold water mass composition of particulate organic carbon, organic detrital particulate organic carbon in 30 m water depth above the water from the ocean itself (plankton and their excrement and debris), and particulate organic carbon in the bottom water is bottom The organic layer of sediment resuspension generated and its decomposition products. And between the southern waters of the bottom water of particulate organic matter in 5 13CPOC significant difference (P0.01), to a certain extent reflects the migration of terrigenous matter, southern waters sediments mainly in the Yangtze River, and surface sediments from the cold water mass of the Yellow River as the main material of water. In particulate organic matter 15NPN values decreased with the increase of water depth, the main source of organic matter decomposition and mineralization. (4) different plankton net collected phytoplankton showed stable isotope distribution of carbon, nitrogen, and planktonic primary production process of animal abundance are two factors affecting the distribution of small plankton net. The phytoplankton collected 13C values with the increase of phytoplankton abundance increased; while the large, medium-sized plankton net collected zooplankton abundance of planktonic animal animal with delta 13C increases. The delta 15N values of plankton collected from three kinds of plankton net were compared. The results showed that plankton collected from three nets contained phytoplankton and zooplankton. The proportion of phytoplankton collected from small plankton network was larger than that of plankton.

【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q178.53

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