Collaborative Research: Environmental Controls on Anammox and Denitrification Rates in Estuarine and Marine Sediments

合作研究：河口和海洋沉积物中厌氧氨氧化和反硝化率的环境控制

• 批准号: 0852289
• 负责人: Jeremy Rich
• 金额: $ 44.65万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0852289&HistoricalAwards=false
• 关键词: Collaborative; Research; Environmental; Controls; Anammox

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The newly discovered process of anaerobic ammonium oxidation (anammox) is an important process in marine environments. The contribution of anammox to global N budgets remains highly uncertain, however. To develop a predictive understanding of nitrogen sinks, comprehensive knowledge on the dynamics of environmental controls that trigger a switch from heterotrophic denitrification to anammox is necessary.In this project, researchers from Brown University and the Ecosystems Center at the Marine Biological Laboratory will test the hypothesis that coupled variation in organic matter and nitrate delivery to the zone of anoxic nitrate respiration drives the switch from heterotrophic denitrification to anammox. They will assess this hypothesis by integrating modeling, laboratory experiments, and field measurements, with the following three objectives: (1) to develop and empirically test bioreaction network models to predict the relative flux of nitrogen sink pathways under varying organic carbon and nitrate; (2) to test the interactive effects of varying organic matter and nitrate delivery rates in sediment microcosm experiments; and (3) to conduct field measurements along natural environmental gradients in Massachusetts Bay and Plum Island Sound Estuary.The microcosm experiment should provide a direct test of the hypothesis that anammox is favored under conditions when nitrate delivery rates are high relative to organic matter loading. The field measurements will test the predictive power of models under in situ conditions. In addition to nutrient flux measurements and sediment porewater profiles, anammox and denitrification rates will be measured using two methods, based on the isotope pairing technique: conventional slurries and intact cores under in situ conditions.Broader impacts: Theoretical and methodological advances from this research will be distributed to the community through the Denitrification Research Coordination Network. The proposed research will support a graduate student and a postdoctoral researcher in the Brown-MBL program, strengthening institutional partnerships to the mutual benefit of the graduate student, postdoctoral researcher and PIs. Undergraduate students will be involved in summer research projects, as well as educational outreach activities through Brown University's ARISE program in local high schools that serve racially diverse students.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。新发现的厌氧氨氧化（anammox）过程是海洋环境中的一个重要过程。然而，厌氧氨氧化对全球氮预算的贡献仍然高度不确定。为了发展对氮汇的预测性理解，有必要全面了解触发从异养反硝化到厌氧氨氧化转换的环境控制动力学。在这个项目中，来自布朗大学和海洋生物实验室生态系统中心的研究人员将测试一个假设，即有机物质和硝酸盐向缺氧硝酸盐呼吸区输送的耦合变化驱动了从异养反硝化到厌氧氨氧化的转变。他们将通过综合建模、实验室实验和实地测量来评估这一假设，并实现以下三个目标：(1)开发和实证测试生物反应网络模型，以预测不同有机碳和硝酸盐下氮汇途径的相对通量；(2)在沉积物微观环境实验中测试不同有机质和硝酸盐输送速率的交互效应；(3)在麻萨诸塞湾和梅岛河口沿自然环境梯度进行野外测量。微观实验应该提供一个假设的直接测试，即在硝酸盐输送率相对于有机物负荷高的条件下厌氧氨氧化是有利的。现场测量将测试模型在现场条件下的预测能力。除了养分通量测量和沉积物孔隙水剖面外，厌氧氨氧化和反硝化速率将使用基于同位素配对技术的两种方法进行测量：常规泥浆和原位条件下的完整岩心。更广泛的影响：本研究的理论和方法进展将通过反硝化研究协调网络向社区传播。拟议的研究将支持布朗大学mbl项目的一名研究生和一名博士后研究员，加强机构伙伴关系，使研究生、博士后研究员和pi相互受益。本科生将参与暑期研究项目，以及通过布朗大学在当地高中的ARISE项目开展的教育推广活动，该项目为不同种族的学生提供服务。