Spatial and seasonal change in algal community structure and its interaction with nutrient dynamics in a gravel-bed urban river

被引:6
|
作者
Zhao, Feng [1 ,2 ]
Xu, Hai [1 ]
Kang, Lijuan [1 ]
Zhao, Xingchen [1 ]
机构
[1] Chinese Acad Sci, Nanjing Inst Geog & Limnol, State Key Lab Lake & Environm, Nanjing 210008, Peoples R China
[2] Jiangnan Univ, Sch Environm & Civil Engn, Wuxi 214122, Jiangsu, Peoples R China
基金
中国国家自然科学基金;
关键词
Harmful algal blooms; Algal community structure; Gravel-bed urban river; River Xin'an; EUTROPHIC LAKE TAIHU; NITROGEN-FIXATION; DENITRIFICATION RATES; CLIMATE-CHANGE; WATER COLUMN; FRESH-WATER; SEDIMENT; CYANOBACTERIA; ECOSYSTEMS; MANAGEMENT;
D O I
10.1016/j.jhazmat.2021.127775
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Harmful algal blooms frequently occur in urban rivers due to intense human activities. However, little is known about the change in algal community structure and its interactions with nutrient dynamics in gravel-bed urban rivers. In present study, water samples were collected from a gravel-bed River Xin' an, China for five months over four seasons and a rainy month to measure algal community structure, dissolved nitrogen gas (N-2) and Argon (Ar) concentrations, and other water quality parameters. The results showed that the harmful Cyanophyta accounted for 31.6 +/- 24.1% of the total community in the hot season while Bacillariophyta contributed more than 60% to the community in the other three seasons. The N-2 was supersaturated in the moderate and cold seasons but it was unsaturated in the hot season, along with high concentrations of nitrogen-fixing cyanobacteria (Anabaena), indicating that the nitrogen fixation capacity was strong and even stronger than denitrification and anammox in the hot season. However, nitrogen fixation was not the main source of nitrogen in the water column. The concentrations of nutrients and Chla in the downstream river were significantly higher than those in the upstream river (p < 0.001 for nutrients and p = 0.029 for Chla), suggesting that human activities along the river greatly affected nutrient concentrations, as well as algal growth. Our study provides new insights into the algal community succession in a gravel-bed urban river and puts forward effective measures such as controlling exogenous nutrient input and dredging organic sediment for mitigating the harmful algal blooms in urban rivers.
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页数:10
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