Atmospheric nitrogen deposition to forest and estuary environments in the Pearl River Delta region, southern China

• Published in: Tellus: Series B, Chemical and Physical Meteorology
• Main Authors: Xuemei Wang, Zhiyong Wu, Min Shao, Yunting Fang, Leiming Zhang, Fei Chen, Pak-wai Chan, Qi Fan, Qian Wang, Shengjie Zhu, Ruoyu Bao
• Format: Article
• Language: English
• Published: Stockholm University Press 2013-09-01
• Subjects: wet deposition; dry deposition; aqueous surface; organic nitrogen; ammonium; nitrate
• Online Access: http://www.tellusb.net/index.php/tellusb/article/download/20480/pdf_1

Due to its significant ecological and climate consequences, atmospheric nitrogen (N) deposition is a growing global concern, especially in the severely N-polluted regions such as the Pearl River Delta (PRD) region of southern China. One-year measurements of reactive N species, including ammonium nitrogen ( -N), nitrate nitrogen (-N) and total organic nitrogen (ON) in dry and wet deposition, were conducted using an automated wet–dry sampler incorporated with a DDAS (dry deposition on aqueous surface) sampling device at Dinghushan (DHS), a natural forest site in the northwest of PRD and at Hengmen (HM), an estuary site in the south of PRD during 2006–2007. Total deposition fluxes of N at DHS and HM were up to 48.2 and 37.8 kg ha−1 yr−1, respectively, with most of the deposition occurring in the rainy season. Wet deposition was the dominant form, contributing 65–70% to the total deposition. -N was the largest contributor to the total N deposition at DHS (47%) due to significant influence of agriculture emissions. ON was the most important N component at HM (41%), which is probably attributed to the marine sources. However, -N deposition is increasing rapidly recently and is expected to be more important in the near future. The current N deposition level in PRD is much higher than those in Europe and North America. Great challenges exist in reducing reactive N emission in this region. Thus, a scenario of rising N deposition in PRD in the near future cannot be ruled out. The environmental consequences due to elevated N deposition should therefore be paid more attention in the future.