title: The composition, spatial patterns, and influencing factors of atmospheric wet nitrogen deposition in Chinese terrestrial ecosystems.
abstract: Atmospheric nitrogen (N) deposition is an important component of the global N cycle, and is a key source of biologically available N. Understanding the spatio-temporal patterns and influencing factors of N deposition is essential to evaluate its ecological effects on terrestrial ecosystems, and to provide a scientific basis for global change research. In this study, we monitored the monthly atmospheric N deposition in rainfall at 41 stations from the Chinese Ecosystem Research Network through measuring total N (TN), total dissolved N (TDN), ammonium (NH4+-N), and nitrate (NO3--N). The results showed that the atmospheric wet deposition of TDN, NH4+-N, and NO3--N were 13.69, 7.25, and 5.93 kg N ha(-1) yr(-1), respectively. The deposition of TN and total particulate N (TPN) was 18.02 and 4.33 kg N ha(-1) yr(-1) respectively, in 2013. TPN accounted for 24% of TN, while NH4+-N and NO3--N made up 40% and 33%, respectively, confirming the assumption that atmospheric wet N deposition would be underestimated without particulate N in rainfall. The N deposition was higher in Central and Southern China, and lower in North-west, North-east, Inner Mongolia, and Qinghai-Tibet regions. Precipitation, N fertilizer use, and energy consumption were significantly correlated with wet N deposition (all p<0.01). Models that included precipitation and N fertilizer can explain 80-91% of the variability in wet N deposition. Our findings reveal, for the first time, the composition of the wet N deposition in China at different scales and highlight the importance of TPN.
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jianxing
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: henp@igsnrr.ac.cn.
authors.forename: Nianpeng
authors.initials: N
authors.lastname: He
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: qfwang@igsnrr.ac.cn.
authors.forename: Qiufeng
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Guofu
authors.initials: G
authors.lastname: Yuan
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ding
authors.initials: D
authors.lastname: Wen
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Guirui
authors.initials: G
authors.lastname: Yu
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Jia
keywords: Composition; Influencing factors; Nitrogen; Spatial pattern; Wet deposition