CAREER: Salt marsh restorations: a structured experiment for learning and teaching about salt marshes, microbial diversity, and ecosystem function

近年来，盐沼受到了广泛的关注，因为它们提供了许多基本的生态系统服务，包括碳固存和氮去除。对沼泽作为碳汇的强烈兴趣可能会刺激新的计划，通过恢复退化的湿地来抵消碳排放，这引发了一系列关于沼泽恢复能否成功恢复其他生态系统功能的问题。盐沼的一个关键生态系统功能是它们通过被称为反硝化的微生物过程去除生物可利用氮的能力。由于施肥和燃烧化石燃料等人类活动，生物上可利用的氮正以越来越快的速度进入沿海生态系统。当这些氮进入沿海水域时，可能会导致与富营养化相关的一系列负面环境影响，包括被称为沿海死区的低氧水域的面积增加。生活在盐沼中的微生物能够通过将这些多余的生物可利用氮转化为氮气来去除一部分，这表明盐沼恢复是有益的，然而，需要更多的信息来了解这些微生物如何应对与恢复相关的环境变化。这项研究将为新英格兰盐沼的恢复如何改变沼泽去除生物可用氮的能力提供新的见解，并将通过原位率测量、环境宏基因组学和全基因组测序的结合，增加对微生物生理学的理解，这些微生物是这一关键生物地球化学途径的基础。本研究结果将为盐沼恢复从业者提供重要的新信息，帮助他们了解哪些条件最有可能成功恢复退化盐沼的反硝化能力，使其达到与未受干扰的盐沼相当的水平。这项工作还将通过两种机制加强科学基础设施和知识转移。首先，它将培养一名早期职业女性科学家、一名博士后学者和两名研究生。其次，关于盐沼反硝化能力的研究将被纳入马萨诸塞大学波士顿分校（University of Massachusetts Boston）本科生的第一年研讨会。马萨诸塞大学波士顿分校是该市唯一一所公立大学，服务于大量少数民族和第一代大学生。这个研讨会项目的目的是通过在他们大学生涯的早期让他们参与研究经验来增加对有风险的生物学专业学生的保留。通过与马萨诸塞州生态恢复部的合作，学生们将与利益相关者会面，在大波士顿地区最近恢复的沼泽中设计和开展研究，并将他们的发现报告给利益相关者。这种社区参与的奖学金提供了一种独特的机制，向利益相关者传播信息，并以一种促进问责制的方式吸引学生参与科学过程，产生更高质量的成果，并激发他们对生态领域的兴趣。

Salt marshes have received a great deal of attention recently because they provide a number of essential ecosystem services, including carbon sequestration and nitrogen removal. Strong interest in marshes as carbon sinks is likely to spur new programs to offset carbon emissions by restoring degraded wetlands, raising a host of questions concerning whether marsh restorations can successfully rehabilitate other ecosystem functions. A key ecosystem functions of salt marshes is their ability to remove biologically available nitrogen through a microbial process known as denitrification. Biologically available nitrogen is entering coastal ecosystems at increasing rates as a result of human activities such as application of fertilizers and combustion of fossil fuels. When this nitrogen makes its way to coastal waters it can result in a host of negative environmental effects associated with eutrophication, including increasing areas of low oxygen water known as coastal dead zones. The microbes living in salt marshes are able to remove portions of this excess biologically available nitrogen by converting it back to nitrogen gas, suggesting a benefit of salt marsh restoration, however, more information is needed regarding how these microbes may respond to environmental changes associated with restoration. This study will provide new insight on how restoration of a New England salt marsh will alter the capacity of the marsh to remove biologically available nitrogen and will increase understanding of the physiology of the microbes that underlie this critical biogeochemical pathway through a combination of in situ rate measurements, environmental metagenomics, and whole genome sequencing. The results of this research will provide important new information to restoration practitioners on the conditions that are mostly likely to successfully restore the denitrification capacity of degraded salt marshes so that they reach parity with undisturbed marshes. This work will also enhance scientific infrastructure and knowledge transfer through two mechanisms. First, it will train one early career female scientist, a postdoctoral scholar, and two graduate students. Second, research on the denitrification capacity of salt marshes will be incorporated into a First Year Seminar for undergraduate students at the University of Massachusetts Boston, the only public university in the city, which serves a large minority and first generation college student population. This seminar program is designed to increase retention of at risk biology majors by engaging them in research experiences in the early days of their college career. Through collaborations with the Massachusetts Department of Ecological Restoration, the students will meet with stakeholders, design and carry out research in recently restored marshes in the greater Boston area, and report their findings back to the stakeholders. This community-engaged scholarship provides a unique mechanism to disseminate information to stakeholders and it engages students in the scientific process in a way that promotes accountability, generates higher quality outcomes and excites them about the field of ecology.