|符亦舒,何虎,何宏业,马路生,苏雅玲,刘正文.不同水体营养盐浓度下沉积物添加镧改性膨润土(Phoslock®)对轮叶黑藻(Hydrilla verticillata)生长的影响.湖泊科学,2021,33(2):388-396. DOI:10.18307/2021.0209
|Fu Yishu,He Hu,He Hongye,Ma Lusheng,Su Yaling,Liu Zhengwen.Effect of addition of lanthanum-modified bentonite(Phoslock®) in sediments on growth of Hydrilla verticillata under different water nutrient concentration. J. Lake Sci.2021,33(2):388-396. DOI:10.18307/2021.0209
|关键词: 水体营养盐 沉积物 轮叶黑藻 镧改性膨润土(锁磷剂) 生态恢复
|Effect of addition of lanthanum-modified bentonite(Phoslock®) in sediments on growth of Hydrilla verticillata under different water nutrient concentration
Fu Yishu1, He Hu2, He Hongye1, Ma Lusheng2, Su Yaling2, Liu Zhengwen1,2
1.Department of Ecology and Institute of Hydrobiology, Jinan University, Guangzhou 510632, P. R. China;2.Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China
|Hydrilla verticillata is a common submerged plant in shallow lakes in China, and is often used as a pioneer species in lake ecological restoration projects. However, the Hydrilla verticillata tends to overgrowth, forming a canopy which affects other functions of lakes. Lanthanum-modified bentonite (Phoslock®) can effectively reduce the bioavailable phosphorus content in sediments. In recent years, it has been used to control phosphorus release from lake sediments. Its impact on the growth and morphology of Hydrilla verticillata remains to be clarified. In this study, two treatments with and without Phoslock® in the sediments were set up to investigate the effects of Phoslock® on the growth and morphological characteristics of Hydrilla verticillata under two different water nutrient concentrations. The results show that:1) After adding Phoslock® to the sediments, the bioavailable phosphorus concentration, such as Fe/Mn combined phosphorus (BD-P), organic phosphorus (Org-P), Aluminum-bound phosphorus (Al-P), is significantly reduced, while the non-bioavailable phosphorus concentration, such as Calcium-bound phosphorus (Ca-P), is significantly increased. 2) The addition of Phoslock® in the sediments significantly reduced the biomass and growth rate of the Hydrilla verticillata. The plant height and aboveground biomass of Phoslock® group were significantly lower than those without Phoslock®; on the contrary, the addition of Phoslock® significantly increased the root length of the plant and the underground biomass, and increased the plant's root-shoot ratio. 3) The effect of Phoslock® on the growth of Hydrilla verticillata is related to the concentration of nutrients in the water, and the effect of Phoslock® on plant growth and morphological characteristics is more significant in low-nutrient water. Overall, this study shows that the addition of Phoslock® can effectively reduce the concentration of bioavailable phosphorus in sediments and inhibit the growth of Hydrilla verticillata, and this effect is more significant when the concentration of nutrients in the water is reduced.
|Key words: Water nutrient sediment Hydrilla verticillata lanthanum-modified bentonite (Phoslock®) ecological restoration