Changes in the ecosystem structure and function of a cyanobacteria bloom-dominated,shallow lake after tenyear eutrophication management  

作　　者：Min PAN Jinyan DONG Zhizhong ZHANG Liyuan ZHANG Yanying GUO Jiaojiao YANG Licheng HUANG Chunbo WANG Kun SHAN Haijun WANG Yongding LIU 

机构地区：[1]Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province,Kunming Dianchi&Plateau Lakes Institute,Kunming 650228,China [2]Institute for Ecological Research and Pollution Control of Plateau Lakes,School of Ecology and Environmental Science,Yunnan Key Laboratory of Ecological Protection and Resource Utilization of River-lake Networks,Yunnan University,Kunming 650500,China [3]Kunming Fisheries Research Institute,Kunming 650021,China [4]Chongqing Institute of Green and Intelligent Technology,Chinese Academy of Sciences,Chongqing 401122,China [5]Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China

出　　处：《Journal of Oceanology and Limnology》2024年第6期1726-1740,共15页海洋湖沼学报（英文）

基　　金：Supported by the Yunnan-Kunming Major Science and Technology Project(No.202202AH210006);the Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province Project(No.202305AM340008);the Yunnan-Kunming Liu Yongding Academician Workstation Funds(No.YSZJGZZ-2020018);the Yunnan Science and Technology Commission(Nos.202401AS070119,202103AC100001);the National Natural Science Foundation of China(No.52379081)。

摘　　要：Large and shallow lakes are widely influenced by multiple anthropogenic stressors,including eutrophication.Normally,diverse strategies of eutrophication management are needed to restore the lake ecosystems.Dianchi Lake,a subtropical plateau lake in Yunnan Province,SW China,has long experienced the effects of eutrophication and cyanobacterial blooms.To mitigate the eutrophication of Dianchi Lake,various efforts have been implemented since 2000,including reducing nutrient inputs,reestablishing aquatic macrophytes in lakeside zones,manipulating fishes and so on.However,little is known about the changes in its ecosystem structure and function after long-term efforts of eutrophication management in the lake.Therefore,this study on such changes was conducted by comparing the field data-based Ecopath models between 2009 and 2019,a decade marked by a rapid implementation of eutrophication management policies.Results show that both top-down and bottom-up processes have influenced the ecosystem structure and function.First,over this decade,nutrient reduction significantly reduced phytoplankton biomass by 49.4%.Nutrient recycling and path length in food web began to decrease,as indicated by the decrease of Finn's cycling index and Finn's mean path length.Secondly,fishing management strategy has greatly changed the composition of fish assemblage,which was dominated by the small zooplantivorous fishes with ecological niche overlapping with shrimps.In general,the stability of the ecosystem has been decreasing,due to the dramatic decrease in zooplankton biomass(83.67%)and hence a collapse of the microbial loop in the food web.Therefore,we strongly advocate the persistent efforts to mitigate the risk of recurrent cyanobacteria blooms in Dianchi Lake,necessitating stricter regulation of nutrient levels and implementing effective fish population management techniques.

关 键 词：Dianchi Lake ECOPATH ecosystem property cyanobacterial bloom nutrient reduction fish manipulation 

分 类 号：X52[环境科学与工程—环境工程]