Influence of algal bloom degradation on nutrient release at the sediment–water interface in Lake Taihu, China
Influence of algal bloom degradation on nutrient release at the sediment–water interface in Lake Taihu, China
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DOI：
10.1007/s11356-012-1084-9
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发表时间：
2013-03
影响因子：
5.8
通讯作者：
Mengyuan Zhu;G. Zhu;Linlin Zhao;Xin Yao;Yunlin Zhang;G. Gao;B. Qin
中科院分区：
文献类型：
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作者：
Mengyuan Zhu;G. Zhu;Linlin Zhao;Xin Yao;Yunlin Zhang;G. Gao;B. Qin
藻类水华会严重影响湖泊的营养循环。为了了解内部营养盐释放如何响应于水华衰减，在中国富营养化太湖的4个不同区域的22个站点采集了水和沉积物柱，并在实验室中培养，以研究大规模水华衰减对沉积物营养盐释放的影响。柱试验包括三个处理：（1）水和沉积物（WS）;（2）水和藻类水华（WA）;（3）水，沉积物，藻类水华（WSA）。在培养期间记录溶解氧（DO）、总氮（TN）、总磷（TP）、铵（NH 4 +-N）和正磷酸盐（PO 43 −-P）的浓度。藻类物质的腐烂导致DO比无藻类对照组下降得更快，并导致水中NH 4 +-N和PO 43 −-P显著增加。孵化过程中存在的藻类沉积物营养剖面上有一个区域变量的影响。在没有腐烂的藻类（治疗WS），沉积物营养盐浓度在孵化过程中下降。在水华（WSA）的存在下，沉积物从河口释放到上覆水的P，而来自其他地区的沉积物吸收从水中过剩的P。实验结果表明，尽管太湖水体与大气的氧交换比柱状水体强，但藻类的大规模腐烂将显著影响沉积物-水界面的养分循环，并可能转移沉积物作为“容器”或“供应者”的功能。影响的程度取决于沉积物的物理化学性质。
Algal bloom could drastically influence the nutrient cycling in lakes. To understand how the internal nutrient release responds to algal bloom decay, water and sediment columns were sampled at 22 sites from four distinct regions of China’s eutrophic Lake Taihu and incubated in the laboratory to examine the influence of massive algal bloom decay on nutrient release from sediment. The column experiment involved three treatments: (1) water and sediment (WS); (2) water and algal bloom (WA); and (3) water, sediment, and algal bloom (WSA). Concentrations of dissolved oxygen (DO), total nitrogen (TN), total phosphorus (TP), ammonium (NH4+-N), and orthophosphate (PO43−-P) were recorded during incubation. The decay of algal material caused a more rapid decrease in DO than in the algae-free controls and led to significant increases in NH4+-N and PO43−-P in the water. The presence of algae during the incubation had a regionally variable effect on sediment nutrient profiles. In the absence of decaying algae (treatment WS), sediment nutrient concentrations decreased during the incubation. In the presence of blooms (WSA), sediments from the river mouth released P to the overlying water, while sediments from other regions absorbed surplus P from the water. This experiment showed that large-scale algal decay will dramatically affect nutrient cycling at the sediment–water interface and would potentially transfer the function of sediment as “container” or “supplier” in Taihu, although oxygen exchange with atmosphere in lake water was stronger than in columns. The magnitude of the effect depends on the physical–chemical character of the sediments.