水生态学杂志2017，Vol.38Issue(4)：48-56,9.DOI:10.15928/j.1674-3075.2017.04.007
三峡水库小江回水区叶绿素a与环境因子的时空变化
Temporal-spatial Variation of Chlorophyll a and Environmental Factorsin the Xiaojiang River Backwater of Three Gorges Reservoir
摘要
Abstract
Eutrophication in the tributaries of Three Gorges reservoir has intensified since impoundment in 2003 and the ecological impacts have received increasing attention at home and abroad.High nitrogen and phosphorus levels are the primary factors resulting in tributary eutrophication and algal blooms.Hydrological factors, including intrusion of Yangtze River water, lower velocity and extended inundation exacerbate the situation.Comprehensive monitoring and analysis of the hydrology, water quality and aquatic ecology in sensitive areas increases our understanding of the algal bloom mechanism.The Gaoyang section of Xiaojiang River is a typical algal bloom area and was monitoring monthly from January to December 2013.Temporal and spatial distributions and the relationship of hydrology, nutrients and chlorophyll a were analyzed.The objective was to explore the eutrophication mechanism and algal bloom triggers in tributaries of Three Gorges Reservoir.Three sampling sites were set on the left, right and in the middle of the Gaoyang section.In the period from the 20th to 25th of each month, water samples were collected at three depths (surface: 0.5 m from the surface;middle: 1/2 water depth;bottom: 0.5m above the bottom) for determination of total nitrogen (TN), ammonia nitrogen, (NH3-N), nitrate nitrogen (NO3-N), phosphate (PO3-4), total phosphorus (TP) and chlorophyll a.In situ measurements included water temperate, water depth, flow velocity, pH, DO and turbidity.The water was well mixed from October to the following January, but was thermally stratified from March to August.When mixed, the nutrient concentrations in different water layers were not significantly different, but nitrogen and phosphorus concentrations were significantly different among the three layers when stratified.The concentrations of nitrogen and phosphorus were higher in winter (TN:1.52-1.74 mg/L, TP:0.092-0.095 mg/L) than in summer (TN:1.16-1.56 mg/L, TP:0.037-0.085 mg/L) and were affected by the intrusion of water from Three Gorges Reservoir (TGR).Chlorophyll a concentration was higher in summer than in winter and the vertical distribution of Chlorophyll a was affected by stratification.When stratified, the range of Chlorophyll a concentration in surface layer was 18.56-92.23 mg/m3, much higher than in the middle and bottom layers (2.54-21.56 mg/m3).Chlorophyll a in surface water was correlated significantly with nutrients, DO, turbidity, water temperature, and temperature variation between top and bottom (P<0.01).Chlorophyll a in the middle layer was correlated significantly with nutrients, water temperature, transparency, depth and water stability (P<0.01).Chlorophyll a in the bottom layer was correlated with nitrate nitrogen (P<0.01), phosphate (P<0.05) and water depth (P<0.05).To summarize, nutrients were the limiting factor for Chlorophyll a concentration in the Gaoyang section of Xiaojiang River and Chlorophyll a , at all depths, was significantly correlated with nitrate nitrogen and phosphate.关键词
叶绿素a/环境因子/时空变化/小江Key words
Chlorophyll a/environmental factors/Xiaojiang River/correlation analysis分类
生物科学引用本文复制引用
邹曦,潘晓洁,郑志伟,万成炎,丁庆秋,张志永..三峡水库小江回水区叶绿素a与环境因子的时空变化[J].水生态学杂志,2017,38(4):48-56,9.基金项目
国家重点研发专项课题(2016YFC0502206) （2016YFC0502206）
十二五水专项子课题(2013ZX07104-004-002) （2013ZX07104-004-002）
国家自然科学基金项目(51209147). （51209147）
