Forest Filter Effect versus Cold Trapping Effect on the Altitudinal Distribution of PCBs: A Case Study of Mt. Gongga, Eastern Tibetan Plateau
Forest Filter Effect versus Cold Trapping Effect on the Altitudinal Distribution of PCBs: A Case Study of Mt. Gongga, Eastern Tibetan Plateau
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森林过滤效应与冷捕效应对PCBs海拔分布的影响——以青藏高原东部贡嘎山为例
DOI：
10.1021/es5041688
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发表时间：
2014-12-16
影响因子：
11.4
通讯作者：
Zhang, Gan
中科院分区：
文献类型：
--
作者：
Liu, Xin;Li, Jun;Zhang, Gan
据观察，由于冷凝结效应，山区优先在海拔较高的地方积累持久性有机污染物（POPs）。以高有机碳为特征的森林土壤对于持久性有机污染物的陆地储存非常重要。为探讨山区POPs海拔分布的主导因素，我们对青藏高原四川省最高峰贡嘎山东坡9个高程的不同环境基质（土壤、苔藓和空气）中多氯联苯（PCBs）的浓度进行了测定。 24 种测得的 PCB 浓度范围为 O 层土壤中的 41 至 510 pg/g 干重 (dw)（平均值：260 pg/g dw）、苔藓中的 280 至 1200 pg/g dw（平均值：740 pg/g dw）以及 33 至 60 pg/m(3)（平均值：47 pg/m(3)) 在空气中。土壤有机碳是解释 75% 浓度沿海拔梯度变化的关键决定因素。根据主成分分析和多元线性回归，在所有采样点中，森林过滤效应（FFE）的平均贡献大于山地冷诱效应。我们的结果偏离了涉及山区高海拔冷凝结的热力学理论，并强调了 FFE 的重要性。
Mountains are observed to preferentially accumulate persistent organic pollutants (POPs) at higher altitude due to the cold condensation effect. Forest soils characterized by high organic carbon are important for terrestrial storage of POPs. To investigate the dominant factor controlling the altitudinal distribution of POPs in mountainous areas, we measured concentrations of polychlorinated biphenyls (PCBs) in different environmental matrices (soil, moss, and air) from nine elevations on the eastern slope of Mt. Gongga, the highest mountain in Sichuan Province on the Tibetan Plateau. The concentrations of 24 measured PCBs ranged from 41 to 510 pg/g dry weight (dw) (mean: 260 pg/g dw) in the O-horizon soil, 280 to 1200 pg/g dw (mean: 740 pg/g dw) in moss, and 33 to 60 pg/m(3) (mean: 47 pg/m(3)) in air. Soil organic carbon was a key determinant explaining 75% of the variation in concentration along the altitudinal gradient. Across all of the sampling sites, the average contribution of the forest filter effect (FFE) was greater than that of the mountain cold trapping effect based on principal components analysis and multiple linear regression. Our results deviate from the thermodynamic theory involving cold condensation at high altitudes of mountain areas and highlight the importance of the FFE.