| 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黏土矿物组成有关; 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; OC/ON 平均值在6.0~14.0 之间, 判断渤海沉积物中有机质受陆源输入和海洋自生共同影响; 其中,有机碳主要以陆源输入为主, 而有机氮在沉积物表层主要以陆源输入为主, 在沉积物下层则主要来源于海洋自生。 |
| 关键词: 有机碳 氮 磷 硅 沉积物 渤海 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目(NOs.40876054,40730847); 科技部国家重点基础研究发展计划“973”项目(NO.2006CB400602) |
|
| Distribution of biogenic elements in the southern and central Bohai Sea sediments |
|
|
| 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 ratios were 2.38, 0.19 and 0.03 in the surface sediments,lower than the Redfield ratio, which indicated that the decomposition rate of BSi was lower than that of organic matter;The OC/ON ratio was from 6.0 to 14.0,indicating that the organic matter in the southern and central Bohai Sea sediments was mixing source,including terrigenous organic matter and marine source; OC was mainly terrigenous input,and ON was mainly terrigenous input in surface sediments but marine autogenic in the lower layer of sediment cores. |
| Key words: organic carbon nitrogen phosphorus silicon sediment Bohai Sea |
