Particle-size distribution and phosphorus forms as a function of hydrological forcing in the Yellow River
Particle-size distribution and phosphorus forms as a function of hydrological forcing in the Yellow River
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DOI：
10.1007/s11356-015-5567-3
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发表时间：
2016-02
影响因子：
5.8
通讯作者：
Qingzhen Yao;Jun-Tao Du;Hong-tao Chen;Zhi-Gang Yu
中科院分区：
文献类型：
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作者：
Qingzhen Yao;Jun-Tao Du;Hong-tao Chen;Zhi-Gang Yu
从2010年1月至12月每月采集样品，并在2010年6月至7月的水-沉积物调节事件期间进行每日观测。采用连续提取法测定了不同粒径组分中磷的形态，并评估了颗粒磷（PP）的潜在生物利用度。结果表明，土壤中交换态磷、有机态磷、自生磷和难降解态磷均随颗粒粒径的减小而增加，碎屑态磷则随颗粒粒径的减小而减少。不同粒径颗粒物中生物可利用性磷含量差异较大。一般来说，粒径越小，生物有效磷含量越高，其在总磷中所占的比例也越高。水文强迫控制的变化，在主要的P相悬浮沉积物中发现，通过在源和颗粒粒度分布的变化。颗粒大小的变化也可以归因于不同的总悬浮泥沙（TSS）的来源。调水调沙仅能调动河床颗粒物，而暴雨期间土壤侵蚀和径流是主要来源。与“真正悬浮”部分相关的BAPP通量比溶解无机磷（DIP）通量大约200倍。因此，细颗粒物转移到公海很可能伴随着BAPP释放到DIP，并可支持更大的初级和次级生产。
Samples were collected monthly from January to December in 2010, and daily observations were made during the water–sediment regulation event in June–July 2010. Sequential extractions were applied to determine the forms of P in different particle-size fractions and to assess the potential bioavailability of particulate phosphorus (PP). The results indicated that exchangeable phosphorus, organic phosphorus, authigenic phosphorus, and refractory phosphorus increased with the decreasing of particulate size; conversely, detrital phosphorus decreased with the decreasing of particulate size. The content of bioavailable particulate phosphorus (BAPP) varied greatly in different sizes of particles. In general, the smaller the particle size, the higher the content of bioavailable phosphorus and its proportion in total phosphorous was found in these particles. Hydrological forcing controlled the variability in the major P phases found in the suspended sediments via changes in the sources and the particle grain-size distribution. The variation of particle sizes can be attributed also to different total suspended sediment (TSS) sources. Water–sediment regulation (WSR) mobilized only particulate matter from the riverbed, while during the rainstorm soil erosion and runoff were the main source. The BAPP fluxes associated with the “truly suspended” fraction was approximately 200 times larger than the dissolved inorganic phosphorus (DIP) flux. Thus, the transfer of fine particles to the open sea is most probably accompanied by BAPP release to the DIP and can support greater primary and secondary production.