Collaborative Research: New Roles for Reactive Oxygen Species in Mediating Carbon Fluxes at the Terrestrial-Aquatic Interface

合作研究：活性氧在调节陆地-水生界面碳通量中的新作用

• 批准号: 2029686
• 负责人: Michael Wilkins
• 金额: $ 19.97万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2029686&HistoricalAwards=false
• 关键词: Collaborative; Research; New; Roles; Reactive

Wetlands in the north central region of the United States are important ecosystems that play critical roles in the regional carbon cycle and are likely to be dramatically affected by climate change. Rates of greenhouse gas release from these wetlands may increase with warming and offset their ability to sequester carbon. By studying the chemical and microbiological processes in wetland sediments over space and time, predictions of the effects of climate change on these critical habitats will be possible. Documentation of the ecological importance of this region via photography will demonstrate the value of wetlands to a broad audience.The drivers of biogeochemical activity that dictate the emissions of carbon dioxide and methane in small, inland waters are poorly constrained, yet processes in these water bodies play an oversized role in understanding climate change. One process that is poorly understood is the role of chemical reactions in mediating carbon dioxide and methane formation in small lakes and wetlands, especially the abiotic production of reactive oxygen species (ROS) at the sediment-water interface (SWI). The hypothesis for this project is that the reaction of reduced soluble and particulate forms of iron, sulfur, and carbon with trace level oxygen to form ROS at the SWI is an under-appreciated, yet critical, control on microbiological activity and the cycling of carbon in small inland water bodies. Using a combination of field work in the prairie pothole region of North Dakota, controlled laboratory experiments, and mesocosm studies, this work will 1) identify the geochemical drivers of ROS generation at the SWI, 2) determine spatiotemporal patterns of linked pore water chemistry and ROS at the SWI, and 3) track the generation of specific labile carbon substrates produced through ROS-DOM reactions that affect rates of carbon mineralization and methane production in small lake and wetland sediments. A combination of in situ voltammetry measurements, detailed characterization of dissolved and particulate organic matter, iron, and sulfur species, and microbial -omics analyses will be used to understand the coupled biogeochemical processes. A key component of this work is understanding how abiotic ROS driven reactions at the sediment-water interface lead to turnover of terminal electron acceptors and generation of labile microbial substrates. Establishing a baseline understanding of these processes is needed to predict changes in carbon dioxide and methane fluxes under different climate scenarios. The collected data will enable understanding of how biogeochemical cycles are maintained through coupled abiotic/biotic pathways, and how these processes impact carbon cycling in aquatic environments. This approach is also applicable to other systems and the cycling of other elements, such as nitrogen, which may be especially important in urban wetland regions. The societal benefit will be improved understanding of processes that influence, and are influenced by, climate change. To reach as broad an audience as possible regarding the importance of this region, a photographer will document the landscape and its ecological function during field sampling trips.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

美国北部中部地区的湿地是重要的生态系统，在区域碳周期中起着关键作用，可能会受到气候变化的极大影响。从这些湿地释放温室气体的速度可能会随着变暖而增加并抵消其隔离碳的能力。通过在时间和时间上研究湿地沉积物中的化学和微生物过程，可以预测气候变化对这些关键栖息地的影响。通过摄影来证明该地区的生态重要性的文献将证明湿地对广泛的受众的价值。在小型内陆水域中决定了二氧化碳和甲烷排放的生物地球化学活动的驱动力，但在这些水体中的过程受到了不良的限制，但在这些水体中的过程在理解气候变化方面发挥了超大作用。一个鲜为人知的过程是化学反应在小湖泊和湿地中介导二氧化碳和甲烷形成的作用，尤其是在沉积物 - 水界面（SWI）的活性氧（ROS）的非生物产生。该项目的假设是，在SWI上降低了铁，硫和碳与痕量水平的含量氧的反应是对微生物活性的反应不足但至关重要的控制，并且对微生物活性的控制以及碳在小内陆水体中的循环。结合北达科他州的草原坑洞地区，受控实验室实验和中学研究，这项工作将确定SWI的ROS生成的地球化学驱动因素，2）确定在SWI上的链接水化学和3）范围的射击速度，并在SWI上的空间变化，以及3）的生成速度，该速度的生成速度，以及3）的生成速度，3）以及小湖和湿地沉积物中的甲烷生产。将原位伏安法测量，溶解和颗粒有机物，铁和硫的详细表征以及微生物 - 摩体分析的结合，用于了解耦合的生物地球化学过程。这项工作的一个关键组成部分是了解在沉积物 - 水界面处的非生物ROS驱动反应如何导致末端电子受体的离职和不稳定的微生物底物的产生。需要对这些过程建立基线理解，以预测不同气候场景下二氧化碳和甲烷通量的变化。收集的数据将使您能够了解如何通过耦合的非生物/生物途径来维持生物地球化学周期，以及这些过程如何影响水生环境中的碳循环。这种方法还适用于其他系统和其他元素的循环，例如氮，这在城市湿地地区尤为重要。社会利益将得到对影响气候变化的影响并受到影响的过程的理解。为了尽可能广泛地了解该地区的重要性，摄影师将在实地抽样旅行期间记录景观及其生态功能。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力优点和更广泛的影响来通过评估来支持的。