摘要
在金沙江下游梯级电站投产前开展生物完整性评价,为梯级水库水生态健康评价、预警管理和生态修复评估提供技术支持和数据支撑。2017—2018年对金沙江下游干流30个采样点(参照点5个,观测点25个)进行4次野外调查,共鉴定出86种(属)浮游植物,具备较高的物种多样性。以硅藻-绿藻-蓝藻型为主,主要优势类群隶属硅藻门,保持着天然河流浮游植物组成特征。基于浮游生物完整性指数(P-IBI),对4类27个初选指标进行分布范围检验、判别能力检测和相关性分析,构建了总分类单元数、蓝藻门分类单元数、硅藻门分类单元占比、硅藻门细胞密度和绿藻门细胞密度占比等5个核心参数组成的金沙江下游浮游植物生物完整性评估体系。以参照点参数25%分位数法确定评价标准:P-IBI>3.81,健康;3.04~3.81,亚健康;2.67~3.03,一般;2.28~2.66,较差;P-IBI<2.28,极差。评估结果显示金沙江下游河流生态整体处于较差水平,丰水季各样点健康状态优于枯水期,可较好地反映梯级电站投产前关键时期河流健康状态。
In this study,we evaluated the aquatic ecosystem health of the cascaded reservoirs in the lower Jinsha River before the cascaded hydropower stations began operating.The evaluation was based on the phytoplanktonic index of biotic integrity(P-IBI)developed as part of this research.The aim of the study was to provide technical and data support for early warning and ecological restoration evaluation of the cascaded reservoirs.The P-IBI evaluation system was based on a phytoplankton investigation carried out at 30 sampling sites in the dry and wet seasons in 2017-2018(5 reference sites and 25 conservation sites)in the lower Jinsha River.A total of 86 phytoplankton species(genera)were identified,reflecting high spe-cies diversity.The phytoplankton community structure belonged to the Bacillariophyta-Chlorophyta-Cy-anophyta type,dominated by Bacillariophyta(43 species,50%),and retaining the composition characteris-tics of phytoplankton in natural rivers.Using the distribution range,discriminant analysis,and Pearson correlation,five core indices(total taxonomic units,cyanobacteria taxonomic units,percentage of Bacil-lariophyta to total taxonomic units,cell density of Bacillariophyta,Chlorophyta cell density as a percent-age of total cell density)were selected from 27 candidate metrics to establish the P-IBI evaluation system.Based on the 25%percentile value of reference sites,the evaluation standard for ecosystem health in the lower Jinsha River was established and five P-IBI grades were set:P-IBI>3.81,healthy;3.03-3.81,sub-healthy;2.67-3.03,fair;2.28-2.66,poor;P-IBI<2.28,very poor.River health was then assessed at each of the 30 sampling sites.During the wet season 1 site was healthy,4 sites were sub-healthy,9 sites were fair,8 sites were poor,and 8 sites were very poor.During the dry season,no sites ranked as healthy,5 sites were sub-healthy,8 sites were fair,8 sites were poor,and 9 sites were very poor.In general,the health sta-tus of the lower Jinsha River was poor,and the ecological condition in the wet season was better than that in dry season.River health evaluation using the P-IBI well reflected conditions before the cascaded hydro-power stations began operations and will support efforts to manage and improve the ecology of the lower Jinsha River.
作者
郜星晨
张琪
苏巍
朱佳志
姜伟
GAO Xingchen;ZHANG Qi;SU Wei;ZHU Jiazhi;JIANG Wei(Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes,Yichang 443100,P.R.China;Chinese Sturgeon Research Institute,China Three Gorges Corporation,Yichang 443100,P.R.China)
出处
《水生态学杂志》
北大核心
2025年第1期11-19,共9页
Journal of Hydroecology
基金
国家重点研发计划课题项目(2022YFC3201802)
中国长江三峡集团有限公司资助项目(WWKY-2020-0079,NBWL202200489)
国家自然科学基金长江水科学研究联合基金项目(Gk924005)。
关键词
浮游植物
生物完整性指数
生态健康评价
梯级水库
金沙江下游
phytoplankton
index of biotic integrity
ecosystem health assessment
cascaded reservoirs
the lower Jinsha River
