Perturbation-free measurement of in situ di-nitrogen emissions from denitrification in nitrate-rich aquatic ecosystems

WATER RESEARCH

卷:109

Article

Qin, Shuping^1,2  Clough, Timothy³  Luo, Jiafa⁴  Wrage-Moennig, Nicole⁵  Oenema, Oene⁶  Zhang, Yuming¹  Hu, Chunsheng¹ 

[1] Chinese Acad Sci, Inst Genet & Dev Biol, Ctr Agr Resources Res, Key Lab Agr Water Resources, 286 Huaizhong Rd, Shijiazhuang 050021, Hebei, Peoples R China

[2] Fujian Agr & Forestry Univ, Coll Resources & Environm, Fujian Prov Key Lab Soil Environm Hlth & Regulat, Fuzhou 350002, Peoples R China

[3] Lincoln Univ, Dept Agr & Life Sci, Lincoln, New Zealand

[4] AgResearch, Land & Environm, Hamilton 3240, New Zealand

[5] Univ Rostock, Dept Agr & Environm, Grassland & Fodder Sci, Rostock, Germany

[6] Wageningen Univ & Res, Alterra, Wageningen, Netherlands

关键词: Denitrification;    Isotopic fractionation;    Reactive nitrogen;    Nitrogen loss;    N2O reduction;   

DOI  :  10.1016/j.watres.2016.11.035

来源: Elsevier

【 摘 要 】

Increased production of reactive nitrogen (Nr) from atmospheric di-nitrogen (N-2) has greatly contributed to increased food production. However, enriching the biosphere with Nr has also caused a series of negative effects on global ecosystems, especially aquatic ecosystems. The main pathway converting Nr back into the atmospheric N-2 pool is the last step in the denitrification process. Despite several attempts, there is still a need for perturbation-free methods for measuring in situ N-2 fluxes from denitrification in aquatic ecosystems at the field scale. Such a method is needed to comprehensively quantify the N-2 fluxes from aquatic ecosystems. Here we observed linear relationships between the delta N-15-N2O signatures and the logarithmically transformed N2O/(N-2+N2O) emission ratios. Through independent measurements, we verified that the perturbation-free N-2 flux from denitrification in nitrate-rich aquatic ecosystems can be inferred from these linear relationships, Our method allowed the determination of field-scale in situ N-2 fluxes from nitrate-rich aquatic ecosystems both with and without overlaying water. The perturbation-free in situ N-2 fluxes observed by the new method were almost one order of magnitude higher than those by the sediment core method. The ability of aquatic ecosystems to remove Nr may previously have been severely underestimated. (C) 2016 Elsevier Ltd. All rights reserved.

【 授权许可】

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