摘要
我国农业流域中,小微水体作为河湖的保护屏障,是重要的磷截留和储存场所,但磷长期累积在特定环境条件下存在释放风险。目前,缺乏小微水体释放风险相关研究和揭示磷截留-释放动态变化特征及影响因素的长期实验。本研究针对典型农业小流域,开展4种类型水塘的沉积物采样和为期6个月的静态培养实验,分析沉积物磷形态特征及沉积物-上覆水界面磷交换动态,评估水塘磷释放风险及影响因素。结果表明:(1)水塘沉积物总磷含量为0.55~3.02 g/kg,与其他类型湿地相比偏高。其中,村落塘磷含量最高,水田塘磷含量最低。(2)在长江中下游农业流域,且水塘存在时间较长的情况下,沉积物-上覆水界面的磷交换表现出明显的季节变化:沉积物在夏秋季向上覆水释放磷,秋冬季从上覆水向沉积物沉降磷。存在年限相似的前提下,水塘的磷汇能力由大到小依次为:林地塘>水田塘=旱地塘>村落塘。研究发现了我国农业流域水塘磷累积量大的现状,揭示了其长期作为磷“汇”、夏秋季转变为磷“源”的功能变化特征,阐明了周边土地利用类型的影响,为改进水塘管理策略提供科学依据,对农业面源污染治理及河湖水环境保护具有广泛的应用价值。
In agricultural watersheds across China,small water bodies serve as important sites for the retention and storage of phosphorus,acting as protective barriers for rivers and lakes.However,under conditions of long-term phosphorus accumulation and specific environmental factors,there is a risk of phosphorus being released.Currently,research on the risk of phosphorus release from small water bodies,and on the dynamic changes in phosphorus retention and release and the influencing factors through long-term experiments,is lacking.This study focuses on a typical agricultural watershed,conducting sediment sampling from four types of pond alongside a six-month static incubation experiment.The study analyses the phosphorus forms in sediments and the phosphorus exchange dynamics at the sediment-water interface to assess the risk of phosphorus release from the ponds and its influencing factors.The results showed that:(1)The total phosphorus(TP)content of pond sediments was higher than that of other types of wetland,ranging from 0.55 to 3.02 g/kg.The highest phosphorus content was found in village ponds,while the lowest was observed in paddy ponds.(2)In the agricultural watersheds of the middle and lower reaches of the Yangtze River and in ponds that have existed for a long time,phosphorus exchange at the sediment-overlying water interface exhibits significant seasonal variation:sediments release phosphorus to the overlying water in summer and autumn,while phosphorus settles from the overlying water to the sediments in autumn and winter.For ponds of a similar age,the phosphorus sink capacity decreased in the following order:forest pond>paddy pond=dryland pond>village pond.This study revealed large accumulations of phosphorus in agricultural ponds in China,highlighting their long-term function as phosphorus sinks which transform into sources during summer and autumn.The findings also clarified the influence of surrounding land use types and provided scientific guidance for improving management strategies for different pond types.These insights are applicable to the control of non-point source pollution and the protection of aquatic environments in rivers and lakes.
作者
柳闻莺
任焕博
易军
时光翔
张亮
霍柯蓉
李思思
Liu Wenying;Ren Huanbo;Yi Jun;Shi Guangxiang;Zhang Liang;Huo Kerong;Li Sisi(Hubei Provincial Engineering Research Center of Non-Point Source Pollution Control,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430077,P.R.China;Key Laboratory for Environment and Disaster Monitoring and Evaluation of Hubei,Jianghan Plain-Honghu Lake Station for Wetland Ecosystem Research,Wuhan 430077,P.R.China;University of Chinese Academy of Sciences,Beijing 100049,P.R.China;College of Urban and Environmental Sciences,Central China Normal University,Wuhan 430079,P.R.China)
出处
《湖泊科学》
北大核心
2026年第1期115-128,共14页
Journal of Lake Sciences
基金
国家自然科学基金项目(42207059)
国家重点研发计划项目(2023YFC3207400)
湖北省自然科学基金项目(2024AFA020,2025AFA108)联合资助
关键词
水塘
沉积物磷形态
农业面源污染
“源汇”转变
磷扩散通量
Pond
phosphorus forms of sediment
agricultural non-point source pollution
“source-sink”transition
phosphorus diffusion flux
