Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6335739 | Atmospheric Environment | 2016 | 7 Pages |
Abstract
Unsurprisingly, the amount of reactive nitrogen circulating annually on land has been doubled because of increasing anthropogenic activities. Exceedingly large amounts of reactive nitrogen (Nr) are likely to disrupt N dynamics and negatively impact the environment and human health. Guizhou Province, a major energy-producing province in southwest China, is suffering from serious long-term acid deposition. However, little work has been done to quantify the levels of atmospheric N deposition in this province, in which some ecologically vulnerable areas have resulted from rocky desertification. In this study, tissue N contents and δ15N signatures in 109 epilithic mosses were analyzed by the ordinary kriging (OK) interpolation technique to determine atmospheric N deposition. Moss N content (1.36-2.65%) showed a significant decrease from west to east, indicating that the spatial variance of TN deposition was the same as that of moss N content, with an average of 27.74 kg N haâ1 yrâ1. Moss δ15N ranged from â5.89â° to â0.72â° and showed an opposite spatial variance compared with moss N contents. Negative δ15N indicated that the main sources for N deposition were urban sewage and agricultural NH3. According to Moss δ15N values, it could be concluded that NH4+-N and NO3â-N were the main components of wet deposition, accounting for 52% and 44% of TN, respectively. The deposition fluxes were 14.49 kg N haâ1 yrâ1 and 12.16 kg N haâ1 yrâ1, respectively. Although the emission flux of NO3â-N far exceeded that of NH4+-N, the amount of NH4+-N deposited on land was larger than that of NO3â-N. N deposition in 99.6% of the province exceeded the critical load for terrestrial ecosystems. High N deposition is the main environmental problem facing Guizhou Province, and recommendations regarding regulatory strategies for mitigating atmospheric N pollution are urgently needed.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Atmospheric Science
Authors
Linglu Qu, Huayun Xiao, Hui Guan, Zhongyi Zhang, Yu Xu,