State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan, 570228, China.
Department of Biology, University of Hartford, West Hartford, CT, 06117, USA.
J Environ Manage. 2022 Oct 1;319:115726. doi: 10.1016/j.jenvman.2022.115726. Epub 2022 Jul 15.
Macrophytes are affected by many natural and human stressors globally but their long-term responses to these multiple stressors are not often quantified. We employed remote sensing and statistical tools to analyze datasets from both short-term (2017-2018) field investigations to explore seasonal patterns, and long-term (1988-2018) Landsat remote-sensing images to detect annual patterns of macrophyte distributions and study their responses to changes in climate, hydrology, and anthropogenic activities in a chain of water diversion lakes in eastern China. We found: 1) biomass and species richness of macrophytes peaked in summer with dominant species of submerged macrophytes Ceratophyllum demersum, Potamogeton pectinatus, and Potamogeton maackianus and floating macrophytes Trapa bispinosa, and non-native species Cabomba caroliniana spread in midstream Luoma Lake and Nansi Lake in summer, while Potamogeton crispus was dominant in all the lakes in spring; 2) water physicochemical parameters (chloride and water depth), lake characteristics (area and water storage), climate factors (air temperature and precipitation), and anthropogenic activities (commercial fishery and urban development) were significantly correlated to the seasonal distribution of macrophytes; 3) long-term data showed a significantly negative correlation between coverage of floating macrophytes and precipitation where the wettest year of 2003 had the lowest coverage of floating macrophytes; and 4) climate (air temperature) and hydrology (water level) were positively correlated with total macrophyte coverage, but human disturbance indexed by the gross domestic product was negatively driving long-term coverage of macrophytes. Our study has important implications for understanding the long-term succession of macrophytes under both natural and human stressors, and for future environmental management and ecological restoration of freshwater lakes.
藻类受全球多种自然和人为胁迫因素的影响，但它们对这些多种胁迫因素的长期响应通常无法量化。我们利用遥感和统计工具，分析了来自短期（2017-2018 年）实地调查的数据集，以探索季节性模式，以及长期（1988-2018 年）Landsat 遥感图像，以检测中国东部一连串调水湖中藻类分布的年度模式，并研究它们对气候、水文学和人为活动变化的响应。我们发现：1）藻类的生物量和物种丰富度在夏季达到峰值，优势种为沉水植物金鱼藻、菹草和马来眼子菜以及浮叶植物菱和外来种卡罗来纳水鳖在夏季在中游的骆马湖和南四湖中扩散，而菹草在所有湖泊中在春季占优势；2）水理化参数（氯和水深）、湖泊特征（面积和储水量）、气候因素（气温和降水）和人为活动（商业渔业和城市发展）与藻类的季节性分布显著相关；3）长期数据显示浮叶植物的覆盖率与降水呈显著负相关，最湿润的 2003 年浮叶植物的覆盖率最低；4）气候（气温）和水文学（水位）与总藻类覆盖率呈正相关，而以国内生产总值衡量的人为干扰则对藻类的长期覆盖率产生负面影响。我们的研究对于理解自然和人为胁迫下藻类的长期演替以及未来淡水湖泊的环境管理和生态恢复具有重要意义。
