Collaborative Research: Effects of Trophic Status Alterations on Pathways of Mercury Methylation in Northern Wetlands

该提案的总体假设是，从小营养型沼泽到微营养型沼泽的转变增加了甲基化率，并改变了微营养型沼泽中甲基化途径，从与微生物共生和发酵相关的甲基化途径转变为由厌氧呼吸驱动的甲基化途径，例如硫酸盐和铁的还原。这个假设是基于pi ？结果表明：(1)阿拉斯加湿地从沼泽到沼泽的转变改变了厌氧分解途径，(2)贫营养型沼泽中共生细菌的优势，以及(3)共生微生物相互作用增强了甲基化。这一假设将通过实地调查和实验室孵化相结合的方式进行检验，包括对阿拉斯加代表营养梯度的湿地进行化学、生物地球化学和分子分析。教育和推广活动包括：(1)制作和传播有关项目和气候变化的视频；(2)指导学生和博士后1名；(3)为高中学生和教师提供现场和实验室实践经验？(4)通过实践研究和融入课堂课程，包括由本项目资助的学生研究，为两所大学的本科生和研究生提供高质量的教育。

The overall hypothesis of this proposal is that the transition from ombrotrophic bogs to minerotrophic fens increases methylation rates and alters methylation pathways from those associated with microbial syntrophy and fermentation to those driven by anaerobic respiration, e.g., sulfate and iron reduction, in minerotrophic fens. This hypothesis is based on PIs? observations of (1) altered anaerobic decomposition pathways with the transition from bogs to fens in Alaskan wetlands, (2) dominance of syntrophic bacteria in an ombrotrophic bog, and (3) enhanced methylation by syntrophic microbial interactions. The hypothesis will be tested using a combination of field surveys and laboratory incubations that encompass chemical, biogeochemical and molecular analyses of wetlands representing trophic gradients in Alaska. The educational and outreach activities include: (1) production and dissemination of videos about the project and climate change; (2) the mentoring of students and a postdoctoral fellow; (3) hands-on field and laboratory experiences for high school students and teachers near PIs? institutions, and (4) high quality education of undergraduate and graduate students at both institutions through hands-on research and integration into classroom curricula, including student research funded by this project.