The interplay between methanotrophy, methanogenesis, and soil geochemistry and its impact on net methane flux to the atmosphere from Arctic soils

摘要(1)技术描述微生物群落在陆地环境中循环碳和氮，是土壤气体通量的核心，包括甲烷（CH4），一种强效温室气体。不幸的是，土壤中甲烷释放的模式正在发生变化，特别是在北极地区，迫切需要更好地了解甲烷菌原位甲烷生成的基础以及甲烷氧化菌的氧化速率和模式；CH4消耗的主要生物机制。PI的实验室工作已经确定，甲烷氧化菌可以获得与矿物质结合的营养物质，并增强其活性。在斯瓦尔巴群岛Ny Ålesund附近的土壤环境中进行的初步实地调查表明，土壤常量养分，如P，可能还有微量金属，如Cu和Ni，可能会限制甲烷营养活性，从而限制甲烷氧化速率。然而，这些地球化学和营养条件如何通过生物活动区（BAZ）变化并影响甲烷生成却知之甚少。来自英国纽卡斯尔大学的两名研究人员将进行所有微生物学、元基因组学和气体通量分析，PI建议对通过BAZ从斯瓦尔巴群岛Ny Ålesund附近超过13个地点收集的土壤进行地球化学、矿物学和同位素分析。迫切需要的资金用于：在复杂的自然北极永久冻土土壤环境中对这些实验室关系进行实地测试，其中不保证成功。2. 测试土壤地球化学是甲烷通量的基本控制这一创新假设，这一假设之前没有经过现场测试，也没有严格的我们提出的采样计划，包括海拔、水文、地貌和基岩岩性的变化。3. 开发用于预测北极环境中甲烷通量的地球化学工具，利用现有地球化学数据或以相对较低成本获得的新数据。(2)北极土壤甲烷通量是全球气候系统的重要输入；这个项目如果成功，可以加强我们预测和模拟全球气候变化的能力。了解土壤地球化学与产甲烷/产甲烷菌活性之间的联系对北极以外的许多自然系统具有广泛的适用性。该项目加强了国际合作（与英国研究人员）。一名理学士将通过这项资助接受培训。PI还与一名高中生物教师合作，为高中生提供研究机会。

Abstract(1) Technical descriptionMicrobial communities recycle carbon and nitrogen in the terrestrial environment and are central to the flux of soil gases, including methane (CH4), a potent greenhouse gas. Unfortunately, patterns of CH4 release from soils, especially in the Arctic are changing, and there is an urgent need to better understand the basis of in situ CH4 production by methanogens and oxidation rates and patterns by methanotrophs; the main biological mechanism for CH4 consumption. Laboratory work by the PI has established that mineral-bound nutrients are accessible to methanotrophs and enhance their activity. Preliminary fieldwork in soil environments near Ny Ålesund, Svalbard suggests that soil macronutrients, such as P, and perhaps trace metals like Cu and Ni may limit methanotroph activity and therefore methane oxidation rates. There is little known, however, how these geochemical and nutrient conditions vary through the biological active zone (BAZ) and impact methanogenesis. In collaboration with two researchers from Newcastle University in the UK, who will perform all microbiological, metagenomic and gas flux analyses, the PI proposes to perform geochemical, mineralogical, and isotopic analyses on soils collected through the BAZ from more than 13 sites in the vicinity of Ny Ålesund, Svalbard. EAGER funds are requested to: 1. Field-test these laboratory relationships in a complex natural Arctic permafrost soil environment, in which success is not guaranteed. 2. Test the innovative hypothesis that soil geochemistry is a fundamental control on methane flux, a hypothesis that has not been field-tested previously, nor with the rigor of our proposed sampling plan that includes variation in altitude, hydrology, geomorphology, and bedrock lithology. 3. Develop a geochemical tool for predicting methane flux in Arctic environments, which utilizes existing geochemical data or new data, acquired at relatively low cost. (2) Broader significance and importanceMethane fluxes from Arctic soils are an important input into the global climate system; this project, if successful, can strengthen our ability to predict and model global climate change. Understanding the link between soil geochemistry and methanotroph/methanogen activity has broad applicability for many natural systems outside of the Arctic. This project strengthens international collaboration (with UK researchers). One B.S. student will be trained through this grant. The PI has also partnered with a biology high school teacher to provide research opportunities for high school students.