Umweltbundesamt, Spittelauer Lände 5, 1090 Vienna, Austria.
Environ Pollut. 2010 Mar;158(3):849-54. doi: 10.1016/j.envpol.2009.09.026. Epub 2009 Oct 30.
Anthropogenic trace element emissions have declined. However, top soils all over the world remain enriched in trace elements. We investigated Pb and Cd migration in forest soils of a remote monitoring site in the Austrian limestone Alps between 1992 and 2004. Large spatial variability masked temporal changes in the mineral soil of Lithic Leptosols (Skeltic), whereas a significant reduction of Pb concentrations in their forest floors occurred. Reductions of concentrations in the less heterogeneous Cambisols (Chromic) were significant. In contrast, virtually no migration of Pb and Cd were found in Stagnosols due to their impeded drainage. Very low element concentrations (<1 microg l(-1)) in field-collected soil solutions using tension lysimeters (0.2 microm nylon filters) imply that migration largely occurred by preferential flow as particulate-bound species during intensive rainfall events. Our results indicate that the extent of Pb and Cd migration in soils is largely influenced by soil type.
人为微量元素排放已经减少。然而，世界各地的表土仍然富含微量元素。我们研究了 1992 年至 2004 年间奥地利石灰岩阿尔卑斯山偏远监测点森林土壤中 Pb 和 Cd 的迁移情况。在 Lithic Leptosols（Skeltic）矿物质土壤中，大的空间变异性掩盖了时间变化，而森林地被层中的 Pb 浓度显著降低。浓度在异质性较小的 Cambisols（Chromic）中的减少是显著的。相比之下，由于排水不畅，Stagnosols 中几乎没有 Pb 和 Cd 的迁移。使用张力渗透计（0.2 微米尼龙过滤器）收集的实地土壤溶液中元素浓度非常低（<1μg l(-1)) ，这表明在强降雨事件中，迁移主要通过优先流作为颗粒结合态物质发生。我们的结果表明，土壤中 Pb 和 Cd 的迁移程度在很大程度上受到土壤类型的影响。
