Dissertation Research, funds for Susan M. Natali: Effects of carbon dioxide and ozone on mercury cycling in forest ecosystems

汞是一种公认的污染物，可能对人类和野生动物的健康构成威胁。 植物叶子的作用是从大气中收集汞，并在衰老时进入土壤。 因此，影响植物生长和功能的环境条件，如二氧化碳和臭氧浓度升高，可能会影响汞在环境中的迁移。 该项目的调查人员先前的工作表明，二氧化碳的增加与土壤中汞浓度的增加有关，但尚不确定这是由于土壤中汞的投入增加还是损失减少。 这项研究将研究在暴露于实验性自由空气二氧化碳/臭氧富集的温带森林中，二氧化碳和臭氧升高对汞循环的影响。 这项研究将确定植物生物量和土壤中的总汞（Hg），落叶、穿透雨和树干径流中的汞输入，以及土壤中的汞流动性。 这项研究将帮助我们了解植物在未来大气中的行为，并为重要环境污染物的循环提供见解。 该研究地点位于密歇根大学的生物站，为教育来自全国各地的不同学生提供了极好的机会。 该研究还将为本科生提供一个机会，完成与该项目相关的独立研究。

Mercury is a well-recognized pollutant that can pose a threat to the health of both humans and wildlife. Plant foliage acts to collect mercury from the atmosphere and, upon senescence, to soils. Environmental conditions that affect plant growth and function, such as elevated carbon dioxide and ozone, may therefore affect the transport of mercury through the environment. Previous work by the investigators of this project has shown that increased carbon dioxide is associated with greater soil mercury concentrations, but it is uncertain if this is due to increased inputs or decreased losses of mercury from soils. This research will examine effects of elevated carbon dioxide and ozone on mercury cycling in a temperate forest exposed to experimental free-air carbon dioxide/ozone enrichment. This study will determine total mercury (Hg) in plant biomass and soils, Hg inputs from leaf litter, throughfall and stemflow, and Hg mobility in soils. This study will help us to understand how plants will behave in a future atmosphere, and provide insights into the cycling of an important environmental contaminant. The study site, at University of Michigan's biological station, provides excellent opportunities for educating diverse students from across the nation in this topic. The study will also provide an opportunity for an undergraduate student to complete an independent research study associated with the project.