Wet-only deposition of atmospheric inorganic nitrogen and associated isotopic characteristics in a typical mountain area, southwestern China

Qiangmei Leng; Jian Cui; Fengwu Zhou; Ke Du; Liuyi Zhang; Chuan Fu; Yuan Liu; Huanbo Wang; Guangming Shi; Min Gao; Fumo Yang; Dongyi He

doi:10.1016/j.scitotenv.2017.10.240

Wet-only deposition of atmospheric inorganic nitrogen and associated isotopic characteristics in a typical mountain area, southwestern China

Sci Total Environ. 2018 Mar:616-617:55-63. doi: 10.1016/j.scitotenv.2017.10.240. Epub 2017 Nov 3.

Authors

Qiangmei Leng¹, Jian Cui², Fengwu Zhou³, Ke Du⁴, Liuyi Zhang¹, Chuan Fu⁵, Yuan Liu³, Huanbo Wang³, Guangming Shi³, Min Gao³, Fumo Yang⁶, Dongyi He³

Affiliations

¹ Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir, Chongqing Three Gorges University, Wanzhou 404000, China; Centre of Atmospheric Environment Research, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
² Centre of Atmospheric Environment Research, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China. Electronic address: cuijian@cigit.ac.cn.
³ Centre of Atmospheric Environment Research, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
⁴ Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary T2N 1N4, Canada.
⁵ Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir, Chongqing Three Gorges University, Wanzhou 404000, China.
⁶ Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir, Chongqing Three Gorges University, Wanzhou 404000, China; Centre of Atmospheric Environment Research, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: fmyang@cigit.ac.cn.

PMID: 29107779
DOI: 10.1016/j.scitotenv.2017.10.240

Abstract

To quantify and compare atmospheric nitrogen (N) deposition and its N isotopic ratio are critical for constraining N sources and effective reduction of reactive N emissions. In this study, a total of 223 rainwater samples were collected by wet-only auto-samplers, and wet-only deposition and isotopic composition (δ¹⁵N) of reduced (NH₄⁺-N) and oxidized (NO₃^--N) N were measured at three typical mountain sites, including an urban (Wanzhou, WZ), a town (Gaoyang, GY) and a rural (Dade, DD) site in Chongqing, southwestern China in 2016. The wet-only inorganic N deposition (DIN, sum of NO₃^--N and NH₄⁺-N) were 17.50, 8.63 and 12.16kgNha^-1yr^-1 at WZ, GY and DD site, respectively. Annual δ¹⁵N-NH₄⁺ values of rainwaters were negative at the urban site (-3.12±3.21‰, WZ) and positive at both town and rural site (0.65±12.51‰, GY; 2.16±6.11‰, DD). Annual δ¹⁵N-NO₃^- values, on the contrary, were positive at the urban site (0.33±7.87‰, WZ) and negative at both town and rural site (-5.59±2.20‰, GY; -0.39±8.89‰, DD). These results reveal the urban site was wet-only DIN hotspot and had a different N source compared with the town-rural site in the mountain area. Moreover, precipitation DIN had a potentially negative risk on both aquatic and forest ecosystems.

Keywords: Chongqing; Compared research; Nitrogen isotope; Nitrogen source; Nitrogen wet deposition.