title: Nitrogen loading and nitrous oxide emissions from a river with multiple hydroelectric reservoirs.
abstract: River networks receive a large fraction of the anthropogenic nitrogen applied to river catchments. The different impacts of the stream nitrogen (N) loading on nitrous oxide (N2O) emissions from various of aquatic ecosystems are still unknown. In this study, direct measurements of water-air interface N2O exchange in different water bodies were conducted. Results showed that the water-air interface N2O exchange from tributaries, hydropower station reservoirs, a main stream, and its estuary were 10.14 ± 13.51, 15.64 ± 10.72, 27.59 ± 20.99, and 15.98 ± 12.26 µg N2O-N m(-2) h(-1), respectively, indicating the strong impacts of human activities on N2O emission rates. The water NO2 (-)-N values predicted the dissolved N2O concentrations better than did the NO3 (-)-N and NH4 (+)-N values, indicating strong denitrification and nitrification processes. The dissolved inorganic N explained 36 % of the variations in the N2O emissions for the whole river network.
authors: State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, South Xiang'an Road, Xiang'an District, Xiamen City, 361102, Fujian Province, China.
authors: Jinsong
authors: J
authors: Chen
authors: Wenzhi
authors: W
authors: Cao
authors: Di
authors: D
authors: Cao
authors: Zheng
authors: Z
authors: Huang
authors: Ying
authors: Y
authors: Liang
mesh_terms: D058440:Denitrification; D004784:Environmental Monitoring; D058465:Nitrification; D009584:Nitrogen / Q000032:analysis*; D009609:Nitrous Oxide / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D009609:Nitrous Oxide; D009584:Nitrogen