title: Dissimilatory nitrate reduction to ammonium conserves nitrogen in anthropogenically affected subtropical mangrove sediments in Southeast China.
abstract: In this study, basic sediment properties, nutrient flux, and nitrogen cycle (including denitrification, anaerobic ammonium oxidation [anammox], nitrification, and dissimilatory nitrate reduction to ammonium [DNRA]) were investigated at two sampling sites with different tree ages in the mangrove region of the Jiulong River Estuary, China. The results show that sediments at mangrove flat area have relatively strong capability to reduce NO3(-), in which the DNRA rate is relatively high (204.53±48.32μmolNm(-2)h(-1)), which is approximately 75.7-85.9% of the total NO3(-) reduction, while the denitrification and anammox rates are relatively low - only approximately 5.6-9.5% and 8.5-14.8% of the total NO3(-) reduction, respectively. Thus, in the nitrogen-enriched subtropical mangrove system, DNRA is the main pathway to reduce NO3(-), and most of the input nitrogen is conserved as NH4(+) in the system, which assures high productivity of the mangrove system.
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, Xiamen University, Xiang'an South Road, Xiamen 361102, China. Electronic address: wzcao@xmu.edu.cn.
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, Xiamen University, Xiang'an South Road, Xiamen 361102, China.
authors.forename: Jingxin
authors.initials: J
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, Xiamen University, Xiang'an South Road, Xiamen 361102, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, Xiamen University, Xiang'an South Road, Xiamen 361102, China.
authors.forename: Baoli
authors.initials: B
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, Xiamen University, Xiang'an South Road, Xiamen 361102, China.
authors.forename: Feifei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Environmental Engineering, National I-Lan University, 1 Sheen Long Road, I-Lan 260, Taiwan.
authors.forename: Changtang
authors.initials: C
authors.lastname: Chang
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D032407:Avicennia; D002681:China; D058440:Denitrification; D019015:Geologic Sediments; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D009584:Nitrogen
keywords: Anaerobic ammonium oxidation (anammox); Denitrification; Dissimilatory nitrate reduction to ammonium (DNRA); Mangrove sediments