BE/CBC: Atmospheric Deposition, Transport, Transformations and Bioavailability of Mercury across a Northern Forest Landscape

该奖项调查了纽约阿迪朗达克一个受汞影响的湖泊中的汞循环，这是一个对酸敏感的森林地区，相对于北美东部的其他湖区，鱼类中的汞浓度很高。本研究的实验前提是冠层过程增强了大气中汞对北方森林生态系统的沉降。汞的运输和转化以及甲基汞向水生生物群的供应受到沉积途径、氧化还原控制的微生物转化和景观特征（如植被、湿地、地表水）的控制。林冠层内的过程加强了汞向森林生态系统的大气沉降。汞进入森林地面，主要是通过雨水和凋落物，可能是一个比湿沉降大两个或更多的因素。在沉积之后，汞经历了一系列复杂的途径和转化，这些途径和转化与其他元素循环相互联系，最终控制甲基汞对水生生物群的供应。这项环境生物复杂性研究的具体目标是量化北部高地阔叶林中汞物种的投入、转化和损失；确定控制汞络合、固定和净甲基化的条件；并评估阿迪朗达克地区大气汞沉降的命运、运输和生物利用度。就更广泛的影响而言，本项目涉及汞在环境中的循环，这是一种在某些浓度和某些环境条件下被确定对人类健康有风险的元素。这项研究将为本科生和研究生提供独特的学习体验。此外，调查人员还设想，利用与阿迪朗达克生态中心和阿迪朗达克博物馆合作开展的一个成功项目，开展广泛的公共教育宣传工作。

This award investigates mercury cycling in a mercury-impacted lake in the Adirondacks of New York, an acid-sensitive forested area with high concentrations of mercury in fish relative to other lake districts in eastern North America.The experimental premise of this research is that canopy processes enhance atmospheric mercury deposition to northern forest ecosystems. The transport and transformation of mercury and the supply of methyl mercury to aquatic biota is controlled by the pathway of deposition, redox-controlled microbial transformations, and landscape characteristics (e.g., vegetation, wetlands, surface waters). Atmospheric deposition of mercury to forest ecosystems is enhanced by processes within the canopy. Mercury entering the forest floor, largely via throughfall and litterfall, may be a factor of two or more greater than wet deposition. Following deposition, mercury undergoes a series of complex pathways and transformations, which interconnect with other element cycles and ultimately control the supply of methyl mercury to aquatic biota.The specific objectives of this study of Biocomplexity in the Environment are to quantify the inputs, transformations and losses of mercury species in an upland northern hardwood forest; determine conditions controlling the complexation, immobilization and net methylation of mercury; and assess the fate, transport and bioavailability of atmospheric mercury deposition across the Adirondack landscape.In terms of broader impacts, this project addresses the cycling of mercury in the environment, an element identified as being of risk to human health in certain concentrations and under certain environmental conditions. The research will provide a unique learning experience for undergraduate and graduate students supported by the research. Also, the investigators envision a wide ranging educational public outreach effort that takes advantage of a successful program being run in conjunction with the Adirondack Ecological Center and the Adirondack Museum.