基于生源要素结构变化驱动的喀斯特水库富营养化特征辨识  

Identification of eutrophication characteristics in karst reservoirs driven by structural dynamics of biogenic elements

作　　者：伍盈盈[1] 肖晶[2] WU Yingying;XIAO Jing(Department of Chemistry and Environmental Engineering,Guizhou Indus-try Polytechnic College,Guiyang 550008,China;Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou Province,Guizhou Normal University,Guiyang 550025,China)

机构地区：[1]贵州工业职业技术学院化学与环境工程系,贵阳550008 [2]贵州师范大学贵州省山地环境信息系统和生态环境保护重点实验室,贵阳550025

出　　处：《生态学杂志》2025年第2期556-565,共10页Chinese Journal of Ecology

基　　金：贵州省高校人文社会科学研究项目(2024RW307)“贵州重点河湖污染治理现状及对策建议研究”资助。

摘　　要：河流筑坝水库水体富营养化是国内外研究关注热点,但富营养化对生源要素含量及结构变化如何响应尚不清楚。本研究以乌江流域上游的红枫湖(HFH)、洪家渡(HJD)、东风渡(DFD)以及乌江渡(WJD)等4座水库为对象,对水库入库河流和库区水体理化指标、浮游植物以及碳(C)、氮(N)、磷(P)、硅(Si)等生源要素溶解态含量进行连续12个月的全年高频监测,探讨水库生源要素时空变化及其对水体富营养化影响机制。结果表明:水库浮游植物丰度年均值大小为HFH(30.27×10^(6) cells·L^(-1))>WJD(6.13×10^(6) cells·L^(-1))>DFD(2.56×10^(6) cells·L^(-1))>HJD(2.13×10^(6) cells·L^(-1)),其中DFD和HJD均以硅藻门为主且丰度占比超53.32%,而HFH和WJD以蓝藻门为主,丰度占比分别为93.36%和68.63%。其次,水库浮游植物吸收固定对生源要素产生截留作用,对DIN、DIP、DSi和DIC的截留通量均值分别为0.13 mmol·m^(-3)·month^(-1)、6.17μmol·m^(-3)·month^(-1)、0.82 mmol·m^(-3)·month^(-1)、14.51 mmol·m^(-3)·month^(-1);DIN/DIP均值小于16,由此判断本研究水库均为DIP限制型水库,其中HFH和WJD水库因DSi/DIP的均值小于20而受DIP和DSi共同限制。此外,富营养化潜力指数(N⁃ICEP和C⁃ICEP)与生源要素及环境因子之间的多元回归R^(2)较高,分别为0.14和0.25,表明DIN和DIC对水库富营养化具有促进作用,DSi限制型水库在DIN和DIC的促进作用下水库富营养化水平高并以蓝藻门等为优势浮游植物,且高DIC含量能促进水库长期保持以蓝藻门占优势的群落特征。因此,喀斯特水库富营养化除了受生源要素含量调控以外,还受生源要素相对比例失衡所影响,研究结果为后期通过监测水体生源要素比例变化来防治水体富营养化提供理论支撑。The eutrophication of reservoir has become a significant research focus globally.However,the response of eutrophication to variations in the concentrations and structure of biogenic elements remains inadequately under⁃stood.We conducted experiments in Hongfeng Lake(HFH),Hongjiadu(HJD),Dongfengdu(DFD)and Wu⁃jiangdu(WJD)reservoirs in the upper reaches of Wujiang River Basin.Water physicochemical indices,phyto⁃plankton,and dissolved concentrations of biogenic elements such as carbon(C),nitrogen(N),phosphorus(P)and silicon(Si)in both inflow rivers and reservoir waters were monitored for 12 months.We analyzed the temporal and spatial variations of biogenic elements in the reservoirs and their influence on water eutrophication.The results showed that annual mean phytoplankton abundance followed an order:HFH(30.27×10^(6) cells·L^(-1))>WJD(6.13×10^(6) cells·L^(-1))>DFD(2.56×10^(6) cells·L^(-1))>HJD(2.13×10^(6) cells·L^(-1)).Both DFD and HJD were primari⁃ly dominated by diatom phylum,which comprised more than 53.32%of total abundance.In contrast,HFH and WJD were predominantly composed of cyanobacterial phylum,with relative abundances of 93.36%and 68.63%,respectively.Reservoirs exhibited a retention effect on biogenic elements due to phytoplankton absorption and fixation.The mean retention fluxes of biogenic elements in the reservoirs were as follows:DIN at 0.13 mmol·m^(-3)·month^(-1),DIP at 6.17μmol·m^(-3)·month^(-1),DSi at 0.82 mmol·m^(-3)·month^(-1),and DIC at 14.51 mmol·m^(-3)·month^(-1).Moreover,the mean DIN/DIP ratio was less than 16,confirming that all reservoirs were DIP⁃limited.Among these,the HFH and WJD reservoirs were co⁃limited by both DIP and DSi,as indicated by a DSi/DIP ratio less than 20.Results of the multiple regression analysis showed strong correlations(R^(2) values of 0.14 and 0.25)between eutrophication potential indices(N⁃ICEP and C⁃ICEP)and both biogenic elements and environmental fac⁃tors,suggesting that DSi⁃limited reservoirs experienced a heightened level of

关 键 词：喀斯特水库 富营养化潜力 生源要素 化学计量比 

分 类 号：X524[环境科学与工程—环境工程]