| 利用石生苔藓氮含量与氮同位素探讨江西省大气氮沉降量和来源 |
| 摘要点击 2401 全文点击 2285 投稿时间：2010-05-11 修订日期：2010-07-28 |
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| 中文关键词 苔藓 氮含量 氮同位素 大气氮沉降 江西省 |
| 英文关键词 moss nitrogen concentration nitrogen isotope atmospheric nitrogen deposition Jiangxi Province |
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| 中文摘要 |
| 2009～2010年在江西省“R>”型酸控区11个地区采集了107个石生细叶小羽藓样品. 通过分析苔藓氮含量和氮同位素组成，以反映大气氮沉降强度和空间分布特征，并甄别大气氮的主要来源. 结果表明，江西省不同地区苔藓平均氮含量变化范围为2.46%～3.48%. 整体上呈现赣西北偏高、赣东南偏低的特点，反映出江西省大气氮沉降水平由北向南逐渐递减的空间分布特征. 江西省城市市区苔藓氮含量（2.79%～3.48%）明显高于郊区氮含量（2.46%～2.74%），说明市区大气氮沉降量高于郊区氮沉降量. 苔藓平均氮同位素均为负值［(-1.96±1.30) ‰～(-9.74±0.25)‰］，并且市区比郊区明显偏负. 市区苔藓偏负的氮同位素值（-5.51‰～-9.74‰）指示了城市污水和人畜排泄物为主要的氨源，而郊区氮同位素值（-4.81‰～-1.96‰）反映出农业活动氨源的贡献. 本研究为大气氮沉降的生态环境效应提供基础资料. |
| 英文摘要 |
| Atmospheric N deposition and N sources in Jiangxi Province were investigated on the basis of the nitrogen concentrations and nitrogen isotope in epilithic mosses which collected from 11 cities of the province during 2009-2010. Mean nitrogen concentrations ranged from 2.46% to 3.48% and showed a significant regional difference. The highest was found in the northwestern of the province and the lowest in the southeastern, reflecting that the level of the atmospheric N deposition gradually decreased from the north to the south in the province. The higher N concentrations in urban mosses than in suburban mosses indicated that the urban areas received higher rates of nitrogen deposition than suburbs areas. Mosses 15N values varied from （-9.74±0.25）‰ to （-1.96±1.30）‰. More negative δ15N values of urban mosses (-5.51‰--9.74‰) indicated that more NH3was released from excretory wastes and sewage, while less negative δ15N values of suburban mosses（-4.81‰--1.96‰) suggested an important contribution from agricultural NH3emission due to entensive fertilizer application. This research provides basic information for further study on the ecological and environmental effects of atmospheric N deposition. |
