Soils and vegetation as a record of anthropogenic pollutants: Mn in the Shale Hills CZO

众所周知，金属是由人类活动排放到空气中，随后沉积到陆地表面的。美国目前的法规要求监测空气排放;然而，过去对陆地表面的输入基本上是未知的。土壤记录了自然和人类活动对地球的通量？的表面，包括大气沉积，因此可以使用质量平衡模型进行分析，以约束输入和输出。在宾夕法尼亚州立大学萨斯奎汉纳页岩山临界区观测站（CZO）开始的工作中，研究人员证明了大气输入污染了宾夕法尼亚州的土壤锰。具体而言，超过一半的锰在土壤中的CZO是最有可能增加的大气沉积从工业来源在过去的200年。 对已发表的土壤数据库的调查表明，锰污染在美国和欧洲的许多工业化地区广泛存在，但高度局部化。这些结果强调，大气传输现在是全球锰循环的一个重要组成部分。在这个项目中，研究人员正在努力了解锰是如何从大气沉积物通过土壤和植被进入溪流的。 锰是重要的影响生态系统的过程，因为它的高反应性，因为它的化合物是氧化还原敏感。锰是光合作用和酶功能所必需的，但也可能对森林和人类有毒。此外，锰氧化物可以螯合大浓度的重金属，可以影响污染物的流动性，并可以影响土壤中的生物功能。该项目将：1）量化CZO植被中Mn的浓度; 2）使用最先进的光谱技术检查CZO中Mn的储存库; 3）开发土壤中Mn循环的模型;以及4）继续挖掘和综合已发表文献中的数据，以测试工业化地区表土普遍Mn污染的假设。拟议的工作将有助于在NSF资助的Shale Hills CZO研究风化层风化的合作努力，该CZO支持了18名学生和17名教师跨多个学科。该项目将支持博士生Beth Herndon。研究人员还将开始与宾夕法尼亚州立大学的一位课程与教学教授合作，改善地球科学课程，并为附近学区的K-8学生开展外展活动。

It is well known that metals are emitted to the air by human activities and subsequently deposited to the land surface. Current regulations in the U.S.A. require that air emissions be monitored; however, past inputs to the land surface are largely unknown. Soils record natural and anthropogenic fluxes to the Earth?s surface, including atmospheric deposition, and can therefore be analyzed using mass balance models to constrain inputs and outputs. In work started at the Penn State Susquehanna Shale Hills Critical Zone Observatory (CZO), the investigator has demonstrated that atmospheric inputs have contaminated soils with Mn in Pennsylvania. Specifically, over half the Mn in the soil in the CZO was most likely added by atmospheric deposition from industrial sources over the last 200 years. Investigation of published soil databases shows that Mn contamination is widespread but highly localized in many industrialized areas in the U.S.A. and Europe. These results emphasize that atmospheric transport is now a critical component of the global Mn cycle. In this project, the investigator is working to understand how Mn moves from atmospheric deposition through the soil and vegetation and into stream water. Mn is important in impacting ecosystem processes because of its high reactivity and because its compounds are redox-sensitive. Mn is essential for photosynthesis and enzymatic function but can also be toxic to forests and humans in high amounts. Additionally, Mn-oxides can sequester large concentrations of heavy metals, can affect mobility of contaminants, and can impact biotic function in soils. This project will 1) quantify concentrations of Mn in CZO vegetation; 2) examine the reservoirs of Mn in the CZO using state-of-the-art spectroscopic techniques; 3) develop models of Mn cycling in the soils; and 4) continue to mine and synthesize data from published literature to test the hypothesis of widespread Mn contamination of topsoils in industrialized regions. The proposed work will contribute to collaborative efforts to study regolith weathering at the NSF-funded Shale Hills CZO, which has supported 18 students and 17 faculty across multiple disciplines. The project will support doctoral student Beth Herndon. The researchers will also begin to collaborate with a Pennsylvania State University professor of Curriculum and Instruction to improve the Earth science curriculum and develop outreach activities for K-8 students in a nearby school district.