摘要: |
从化学结合形式出发,对渤海中南部海区沉积物中OC、N、P、BSi等生源要素的含量进行调查分析,讨论了各生源要素的分布及其影响因素。结果表明:受陆源输入的影响,表层沉积物中各形态氮、磷及有机碳均呈现“近岸高,远岸低”的分布趋势,生物硅的含量分布则与海区浮游硅藻的分布趋势相一致;可交换态氮是总氮中较活跃的部分,占总氮的比例约为3.7%;固定态铵是总氮的主要组成部分,约占总氮的38.4%,其主要与有机质含量及粘土矿物组成有关;渤海表层沉积物中OC/BSi、ON/BSi以及OP/BSi的比值分别为2.38、0.19、0.03,低于Redfield比值,说明有机质优先于生物硅分解;渤海表层沉积物中OC/ON平均值为13.2,且在渤海西北部海区及渤海海峡有较高比值,通过对陆源输入和海洋自生有机质含量的估算得出,渤海表层沉积物中有机碳及有机氮均以陆源输入为主;柱状沉积物OC/ON比值在6.0~14.0之间,且在5cm以浅比值略有减小,说明沉积物中以某种形式富集了ON。 |
关键词: 有机碳 氮 磷 硅 沉积物 渤海 |
DOI: |
分类号:P734.2+5 |
基金项目:国家重点基础研究发展计划(973计划),国家自然科学基金项目(面上项目,重点项目,重大项目) |
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Distribution of Biogenic Elements in the Southern and Central Bohai Sea Sediments |
Li Ling-Wei
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Ocean University of China
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Abstract: |
We studied the distribution of OC, N, P and BSi in the southern and central Bohai
Sea sediments.The results indicated that:Because of the effect of terrigenous input, the concentrations of various forms of nitrogen、phosphorus and organic carbon were higher in the shallow coastal sediments than in the central Bohai Sea, and the distribution of Biogenic Silica had close relationship with the content of diatoms;Exchangeable nitrogen accounted for 3.7% of total nitrogen and fixed ammonium accounted for 38.4% which was affected by the content of organic carbon and the clay mineral composition in the sediments;The OC/BSi, ON/BSi and OP/BSi molar ratios were 2.38, 0.19 and 0.03 in the surface sediments,lower than the Redfield ratio, indicating that the decomposition rate of BSi was lower than that of organic matter; The average molar ratio of OC/ON was 13.2 in surface sediments, which was higher in the northwest of Bohai Sea and Bohai Strait; By estimating of terrigenous organic matter and marine source, OC and ON in surface sediments were mainly terrigenous input; The moalr ratio of OC/ON in sediment cores was from 6.0 to 14.0, which decreased slightly above five centimeters indicating that ON was enriched in sediments. |
Key words: organc carbon nitrogen phosphorus silicon sediment Bohai Sea |