Jiangsu Provincial Academy of Environmental Science, Nanjing, China.
Jiangsu Provincial Key Laboratory of Environmental Engineering, Nanjing, China.
Environ Sci Pollut Res Int. 2023 Feb;30(6):16166-16177. doi: 10.1007/s11356-022-23403-z. Epub 2022 Sep 30.
Eutrophication in inland lakes is occurring frequently with the rapid urbanization, the increases in human population, and the intensive agricultural activities. Traditional management programs focusing on external nutrient reduction failed in recovery of certain aquatic environments where internal nutrient releases are substantial. In this study, we evaluated the effects of aquatic vegetation in altering the phosphorus concentrations in a shallow, eutrophic lake through laboratory flume experiments. Our measurements demonstrated that aquatic vegetation could effectively lower the phosphorus levels in the water column, and the average reduction reached 90% for submerged vegetation and 80% for emergent vegetation. The experimental results showed that the submerged vegetation was effective to reduce phosphorus concentrations in the top and mid layers of pore waters and sediments. Differently, the emergent vegetation would assimilate more phosphorus in the bottom layer due to its deep root distributions. The flowing-water environment favored phosphorus removal for emergent vegetation, while the submerged vegetation was more functional in static waters according to our observations. The flux results showed that phosphorus transports from water columns to leaves, roots to leaves, and sediments to roots were all inhibited in flowing-water environments for submerged vegetation. Oppositely, the fluxes of emergent vegetation groups were all enhanced in flowing waters. Our experiments could inform ecosystem management concerning the potentials of aquatic vegetation in nutrient removal at regional and lake-wide scales.
内陆湖泊富营养化随着城市化的快速发展、人口增长和农业活动的加剧而频繁发生。传统的侧重于减少外部营养物的管理方案在某些内部营养物释放大量的水生环境的恢复中失败了。在这项研究中，我们通过实验室水槽实验评估了水生植被对改变浅水富营养化湖泊中磷浓度的影响。我们的测量表明，水生植被可以有效地降低水柱中的磷水平，平均减少率达到 90%的淹没植被和 80%的挺水植被。实验结果表明，淹没植被可以有效地降低孔隙水和沉积物上层和中层的磷浓度。不同的是，由于其深根分布，挺水植被会在底层吸收更多的磷。流水环境有利于挺水植被去除磷，而根据我们的观察，淹没植被在静止水中的功能更强。通量结果表明，磷在水流环境中从水柱到叶片、从根到叶片以及从沉积物到根的运输都受到抑制。相反，挺水植被的通量在流动水中都得到了增强。我们的实验可以为生态系统管理提供信息，了解水生植被在区域和湖泊范围内去除营养物的潜力。
