【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.更多还原

【Abstract】 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 15 N values varied from(-9.74 ± 0.25)‰ to(-1.96 ± 1.30)‰.More negative δ15 N values of urban mosses(-5.51‰--9.74‰) indicated that more NH3 was released from excretory wastes and sewage,while less negative δ15 N values of suburban mosses(-4.81‰--1.96‰) suggested an important contribution from agricultural NH3 emission due to entensive fertilizer application.This research provides basic information for further study on the ecological and environmental effects of atmospheric N deposition.更多还原