Guo Liangliang, Dai Liangliang, Zheng Jiaoli, Zhou Weicheng, Peng Chengrong, Li Dunhai, Li Genbao
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; Key Laboratory of Geospatial Technology for Middle and Lower Yellow River Regions, Ministry of Education, College of Geography and Environmental Science, Henan University, Kaifeng, 475004, China.
Guizhou Institute of Biology, Guiyang, 550000, China.
J Environ Manage. 2022 Jul 1;313:114977. doi: 10.1016/j.jenvman.2022.114977. Epub 2022 Mar 31.
The process of ecological restoration in eutrophic lakes, often results in the blooming of the filamentous green algae Cladophora. This consequently affects the growth of submerged plants and the restoration of vegetation. However, the blooming process of Cladophora and the environmental factors affecting their growth are poorly understood. This has become a difficult problem in the management of lakes. The study therefore focused on succession process of Cladophora blooms and their driving factors through mesocosm experiments in Caohai Lake. The results of our experiment indicated that Cladophora growth was mainly affected by water temperature, turbidity and soluble reactive phosphorus concentration of the habitat where Elodea nuttallii and Cladophora coexist. Nuisance Cladophora was mainly affected by turbidity (>19.24 NTU) when the water temperature was above 15.7 °C. With increasing Cladophora biomass and decreasing turbidity (<4.88 NTU), Cladophora biomass accumulation was mainly limited by the soluble reactive phosphorus concentration (<3.2 μg/L). Recorded turbidity range of 9.54-13.19 NTU was found to cause dramatic changes in the biomass of Cladophora. The results also showed that the outbreak of Cladophora blooms was mainly attributed to turbidity when the water temperature was appropriate in eutrophic lakes. These findings suggest that successful management efforts should strengthen the monitoring of transparency change in addition to controlling the phosphorus concentration to limit the Cladophora overgrowth on lake ecological restoration.
富营养化湖泊的生态恢复过程常常导致丝状绿藻刚毛藻大量繁殖。这进而影响沉水植物的生长和植被恢复。然而，人们对刚毛藻的繁殖过程及其生长的环境影响因素了解甚少。这已成为湖泊管理中的一个难题。因此，该研究通过在草海进行的围隔实验，聚焦于刚毛藻水华的演替过程及其驱动因素。我们的实验结果表明，刚毛藻的生长主要受伊乐藻和刚毛藻共存生境的水温、浊度和可溶性活性磷浓度影响。当水温高于15.7℃时，有害刚毛藻主要受浊度（>19.24 NTU）影响。随着刚毛藻生物量增加和浊度降低（<4.88 NTU），刚毛藻生物量积累主要受可溶性活性磷浓度（<3.2 μg/L）限制。记录到的9.54 - 13.19 NTU的浊度范围会导致刚毛藻生物量发生显著变化。结果还表明，在富营养化湖泊中，当水温适宜时，刚毛藻水华的爆发主要归因于浊度。这些发现表明，在湖泊生态恢复中，除了控制磷浓度以限制刚毛藻过度生长外，成功的管理措施还应加强对透明度变化的监测。
