Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China.
Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China.
Sci Total Environ. 2018 Jul 1;628-629:687-696. doi: 10.1016/j.scitotenv.2018.02.035. Epub 2018 Feb 20.
Anthropogenic metals adsorbed on suspended fine particles can be deposited on remote and inaccessible high mountains by long-range atmospheric transport. In this study, we investigated the cadmium (Cd) and lead (Pb) in the soils, mosses and rainfall of three transects on the Gongga Mountain, eastern Tibetan Plateau, to understand the mountain interception effects on their atmospheric transport. The concentrations of Cd and Pb in the soils and mosses displayed a pattern of eastern transect>northern transect>western transect. The distribution of Cd and Pb on the eastern transect increased from 2000 to 2900m a.s.l. (above sea level), decreased toward the timberline, and increased again with altitude; on the northern transect, it generally decreased with altitude whereas a distribution trend was not clearly observed on the western transect. The Cd and Pb concentrations in the rainfall of the eastern transect generally decreased with altitude, and they were higher inside forests than outside forests and temporally higher in the winter than the summer. The Pb isotopic ratios coupled with moss bio-monitoring distinguished anthropogenic sources of Cd and Pb on the eastern and northern transects, whereas bedrock weathering was the main source of Cd and Pb on the western transect. We proposed a conceptual model to delineate the effects of terrain, local climate and vegetation on the transport of atmospheric metals. Our results highlighted the high mountains in the eastern Tibetan Plateau as an effective natural barrier limiting atmospheric metal transport.
人为金属吸附在悬浮的细颗粒上，可以通过长距离大气输送而沉积在遥远和难以到达的高山上。在这项研究中，我们调查了贡嘎山三条样带上土壤、苔藓和降水中的镉（Cd）和铅（Pb），以了解高山对它们大气传输的拦截效应。土壤和苔藓中 Cd 和 Pb 的浓度呈现出东样带>北样带>西样带的模式。东样带上 Cd 和 Pb 的分布从 2000 米到 2900 米（海拔）逐渐增加，向林线减少，然后随着海拔再次增加；北样带上则普遍随着海拔降低，而西样带上则没有明显的分布趋势。东样带上的降雨中 Cd 和 Pb 的浓度通常随着海拔的升高而降低，森林内的浓度高于森林外，冬季的浓度高于夏季。Pb 同位素比值结合苔藓生物监测，区分了东样带和北样带上 Cd 和 Pb 的人为来源，而西样带上 Cd 和 Pb 的主要来源是基岩风化。我们提出了一个概念模型来描绘地形、当地气候和植被对大气金属传输的影响。我们的研究结果突出了青藏高原东部的高山是限制大气金属传输的有效天然屏障。
