Dissolved nitrous oxide and emission relating to denitrification across the Poyang Lake aquatic continuum

作     者：Huaxin Wang Lu Zhang Xiaolong Yao Bin Xue Weijin Yan 

作者机构：Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China State Key Laboratory of Lake Science and EnvironmentNanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China Graduate University of the Chinese Academy of SciencesBeijing 200049China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2017年第29卷第2期

页      面：130-140页

核心收录：

学科分类：08[工学] 081501[工学-水文学及水资源] 0815[工学-水利工程] 

基　　金：supported by the Research Program of State Key Laboratory of Lake Science and Environment(No.2012SKL012) CAS Key Project(No.KJZD-EW-TZ-G10) the National Basic Research Program(973)of China(No.2012CB417005) the Poyang Lake Wetland Integrated Research Station for their help on field study 

主　　题：Nitrous oxide gas Nitrogen Dinitrogen gas Denitrification Natural wetlands Poyang Lake 

摘      要：Most aquatic ecosystems contribute elevated N2 O to atmosphere due to increasing anthropogenic nitrogen loading. To further understand the spatial heterogeneity along an aquatic continuum from the upriver to wetland to lake to downriver, the study was conducted on spatial variations in N2 O emission along Poyang Lake aquatic continuum during the flood season from 15 July 2013 to 10 August 2013. The results showed the N2 O concentrations, the ratio of N2O/dinitrogen（N2） gases production, N2 O emission and denitrification rates ranged from 0.10 to 1.11 μg N/L,- 0.007% to 0.051%,- 9.73 to 127 μg N/m2/hr and 1.33 × 104to31.9 × 104μg N2/m2/hr, respectively, across the continuum. The average N2 O concentrations,the ratio of N2O/N2 and N2O emission was significantly lower in wetlands as compared to the rivers and lake（p 〈 0.01）. The significantly high denitrification rate and low N2 O emission together highlighted that most N2 O can be converted into N2 via near complete denitrification in the Poyang Lake wetlands. Our study suggests that the wetlands might impact N2 O budget in an integrated aquatic ecosystems. Moreover, N2 O emission from different aquatic ecosystem should be considered separately when quantifying the regional budget in aquatic ecosystem.