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.
Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Sci Total Environ. 2015 Apr 1;511:777-85. doi: 10.1016/j.scitotenv.2014.12.038. Epub 2015 Jan 22.
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.
大气氮（N）沉降是全球 N 循环的重要组成部分，也是生物可利用 N 的主要来源。了解 N 沉降的时空格局和影响因素对于评估其对陆地生态系统的生态效应至关重要，并且为全球变化研究提供了科学依据。本研究通过测量总 N（TN）、总溶解 N（TDN）、铵（NH4+-N）和硝酸盐（NO3--N），在中国生态系统研究网络的 41 个站点监测了大气降雨中的月 N 沉降。结果表明，TDN、NH4+-N 和 NO3--N 的大气湿沉降分别为 13.69、7.25 和 5.93kgNha-1yr-1。TN 和总颗粒态 N（TPN）的沉降分别为 18.02 和 4.33kgNha-1yr-1。TPN 占 TN 的 24%，而 NH4+-N 和 NO3--N 分别占 40%和 33%，这证实了在没有降雨中颗粒态 N 的情况下，大气湿 N 沉降会被低估的假设。N 沉降在中南地区较高，而在西北、东北、内蒙古和青藏高原地区较低。降水、N 肥使用和能源消耗与湿 N 沉降显著相关（均 p<0.01）。包含降水和 N 肥的模型可以解释 80-91%的湿 N 沉降变化。我们的研究结果首次揭示了中国不同尺度的湿 N 沉降组成，突出了 TPN 的重要性。
