摘要: |
对长江口潮滩表层沉积生磷的赋存形态和含量的研究表明,碎屑 态磷为沉积物中磷的主要形态,约占总磷的62.52%;铁结合态磷和有机磷次之,分别占总磷的18.06%和14.69%;自生磷灰石加钙结合态磷和吸附 态磷最少。综合研究区内的各种理化条件,指出弱吸附态磷、铁结合态磷和有机磷是长江口潮滩潜在生物可利用磷,约占总磷的33.16%,是导致水体富营养化 的潜在因素。上覆水的盐度效应是影响沉积物铁结合态磷含量的关键性因子;而自生磷灰石加钙结合态磷的含量变化则与上覆水的温度、溶氧量及沉积物有机质的分 解有关;有机磷在时间和空间尺度上都存在较大变化,主要与潮滩生物动态过程,即磷的再矿化有关。 |
关键词: 表层沉积物 磷 生物有效性 潮滩 长江口 |
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基金项目:国家自然科学基金资助项目(40131020,49801018);教育部高等学校骨干教师资助计划项目;上海市重点学科资助项目(SHPAD-01) |
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Seasonal accumulation and bioavailabilities of phosphorous in the tidal flat surface sediments from the Yangtze estuary |
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Abstract: |
The species and contents of phosphorus were studied in the tidal flat surface sediments of the Yangtze estuary. The results showed that detrital apatite contributed 62.52% of total phosphorus, which is the main speciation of phosphorus. Iron-bound phosphate and organic phosphate respectively made up 18.06% and 14.69% of total phosphorus. While authigenic apatite plus calcium-bound phosphate and loosely adsorbed phosphate occupied the least of total phosphorus. According to all kinds of physico-chemical conditions in the study area, only loosely adsorbed phosphate, iron-bound phosphate and organic phosphate should be considered as the potential factors for eutrophication, which represented mean proportion of 33.16% of the total phosphorus. Salinity effect on the overlying waters was the key factor to the content of iron-bound phosphate, and authigenic apatite plus calcium-bound phosphate is relative to the water temperature, dissolved oxygen and decomposition of sedimentary organic matters. Organic phosphate was the only form to exhibit significant spatio-temporal variations, which were linked to the remineralization of phosphorus. |
Key words: surface sediment phosphorous bioavailabilities tidal flat the Yangtze estuary |