摘要
为掌握嘉陵江浮游植物群落结构现状,了解环境变化对浮游植物种类组成、数量等造成的影响,初步预测在高密度水电工程的影响下浮游植物群落发展方向,于2019年对嘉陵江水电工程最密集的中游河段进行了分季节调查研究。结果显示:(1)研究水域存在一定程度的污染,主要超标物为总磷。(2)共检出浮游植物7门91属196种,总密度年均值4.23×10^(6)cells/L,以绿藻>硅藻>蓝藻为主要优势门类。与历史数据相比,硅藻种类数与相对密度下降,绿藻、蓝藻种类数和相对密度上升,暗示着嘉陵江水体的富营养化趋势。生物多样性指数结果也显示研究江段存在一定程度的污染。(3)分类回归树(CRT)结果显示,在TP含量丰富,pH较高、水体透光度适中的断面,浮游植物可能会大量增殖。(4)冗余分析(RDA)发现,绿藻各优势种属均表现与水温、总磷的正相关;硅藻中仅有优势度最高的小环藻喜好较高的TP和较低的流速;以适应一定流速的丝状蓝藻为优势的蓝藻门除了喜好高温以外,与水流速度也有一定正关联。总的说来,目前嘉陵江富营养化、水流低速化正在导致喜好清洁、流水环境的硅藻逐渐丢失优势性,喜好高营养、静水环境或微流水环境的绿藻门、蓝藻门与硅藻门小环藻属Cyclotella优势度逐渐增大。在各级电站库区,存在夏季高温季节出现蓝、绿藻水华,初春低温季节则可能出现小环藻优势的硅藻水华的危险。除对全流域水环境进行综合治理降低营养水平外,适时开闸冲水,增大库区流速以降低水华藻类的优势非常有必要。
The middle reaches of the Jialing River have the most intensive hydropower projects, which significantly impact the development of phytoplankton communities in the lower reaches. Based on this, this study conducted a seasonal survey on the reaches in 2019 to investigate the current status of the phytoplankton community structure and analyze the impact of environmental changes on the composition and quantity of phytoplankton species. Specifically, the following research findings have been made. First, there is a certain degree of pollution in the investigated reaches, especially reflected in the exceeding of the total phosphorus(TP) content. Second, a total of 196 species, which belonged to 91 genera in 7 phyla, were identified, and their annual mean of total density was 4.23×10^(6)cells/L. Moreover, the dominant phyla were ordered as Chlorophyta > Bacillariophyta > Cyanophyta. Compared with the historical data, the richness and relative density of Bacillariophyta decreased, while those of Chlorophyta and Cyanophyta increased, suggesting the eutrophication trend of the investigated reaches. Furthermore, the results of the biodiversity index also show a certain degree of pollution in the reaches. Third, the results of Classification and Regression Tree showed that phytoplankton might proliferate in reaches with abundance TP, high pH, and moderate secchi depth. Fourth, according to the Redundancy Analysis, all dominant species of Chlorophyta identified were positively correlated with the water temperature and TP, while only Cyclotella with the highest dominance in the Bacillariophyta species preferred the higher TP and lower flow velocity(FV). Furthermore, the Cyanobacteria dominated by filament strains that adapt to a certain FV preferred high water temperature and were positively correlated with the FV. It is concluded that the current eutrophication and low-speed flow of the Jialing River are the main reasons of the Bacillariophyta that prefer clean water and high FV gradually losing their dominance, and the inc
作者
陶敏
熊钰
李斌
王志坚
黄静
TAO Min;XIONG Yu;LI Bin;WANG Zhi-jian;HUANG Jing(School of Life Sciences,Neijiang Normal University,Neijiang 641112,China;Conservation and Utilization of Fishes resources in the Upper Reaches of the Yangtze River,Key Laboratory of Sichuan Province,Neijiang 641112,China;Key Laboratory of Aquatic Science of Chongqing,Southwest University,Chongqing 400715,China)
出处
《长江流域资源与环境》
CAS
CSSCI
CSCD
北大核心
2021年第7期1680-1694,共15页
Resources and Environment in the Yangtze Basin
基金
农业财政专项(CJDC-2017-12)
四川省科技厅项目(2019YJ0498,2019YJ0397)
内江师范学院校级科研项目(2019YB10,18ZL05)
四川省大学生创新创业训练计划项目(X2020019)。
关键词
嘉陵江
浮游植物
梯级水电站
环境因子
水华
Jialing River
phytoplankton
cascade hydropower stations
environmental factors
algal bloom
