EAR-Climate: Collaborative Research: Methane Dynamics Across Microbe-to-Landscape Scales in Coastal Wetlands

EAR-气候：合作研究：沿海湿地从微生物到景观尺度的甲烷动力学

• 批准号: 2218621
• 负责人: Annette Engel
• 金额: $ 77.9万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2027-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2218621&HistoricalAwards=false
• 关键词: EAR; Climate; Collaborative; Research; Methane

Methane (CH4) is a gas that, although it has a much lower concentration in the atmosphere compared to carbon dioxide (CO2), possesses a much more potent greenhouse effect, possibly accounting for 20-25% of global warming since the Industrial Revolution. Methane has a short residence in the air, so that regulating the emission of this gas can have rapid and profound results for mitigating climate change. The amount of methane in the atmosphere has increased despite reductions in anthropogenic sources; accordingly, the processes of methane production in natural environments must be accurately assessed. Coastal wetlands account for ~40% of global methane emissions and these regions are in constant flux owing to sea-level rise, sediment accumulation, ecological shifts, and landscape dynamics. This project will investigate the present-day controls on methane emissions in coastal wetlands, assess their variability due to sea-level rise, and use field observations and experiments to develop models that integrate the numerous factors that control methane emissions from these environments. The study site will be in coastal Louisiana, which has ~40% of all coastal, tidally influenced fresh and saltwater wetlands in the U.S., and these wetlands experience some of the highest relative sea-level rise rates in the world. Nearly 1 billion people around the globe live in proximity to similar coastal wetlands, so that the results of this research will have broad applicability to solving large-scale problems. The project’s educational and outreach activities will leverage ongoing programs at the participating universities and further include the development of new resources that will be available to students and the public.The proposed spatiotemporal framework will combine field, experimental, and model-based approaches to determine methane emissions from a range of settings (e.g., elevation, salinity, distance from waterways, hydroperiod, temperature, vegetation, soil organic carbon) and time scales (decadal–centennial– millennial) in the Terrebonne-Timbalier Estuary of coastal Louisiana. Some of these vegetated wetland soils emit more methane annually than the soil carbon that they sequester. The research objectives will: i) assess spatiotemporal variability of methane inventories and emissions, ii) quantify soil and organic carbon age and sedimentation history, iii) determine the microbial and functional diversity from soils at different spatiotemporal scales and across geochemical gradients, iv) experimentally assess methane flux due to flooding (e.g., duration, frequency, depth) regime changes, v) integrate landscape change into hydrodynamic and biogeochemical models that account for changes in wetland configuration and sea-level, and iv) evaluate the best numerical parameters to simulate methane dynamics across microbe-to-landscape scales.This project is jointly funded by the Frontier Research In Earth Sciences (FRES) program, the Established Program to Stimulate Competitive Research (EPSCoR), and the Ecosystem Sciences program in the Division of Environmental Biology (DEB).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.

甲烷（CH 4）是一种气体，虽然它在大气中的浓度比二氧化碳（CO2）低得多，但具有更强的温室效应，可能占自工业革命以来全球变暖的20-25%。甲烷在空气中的停留时间很短，因此控制这种气体的排放可以对减缓气候变化产生迅速而深远的影响。尽管人为排放源减少，但大气中的甲烷量却增加了;因此，必须准确评估自然环境中甲烷的产生过程。沿海湿地约占全球甲烷排放量的40%，由于海平面上升，沉积物积累，生态变化和景观动态，这些地区处于不断变化之中。该项目将调查目前对沿海湿地甲烷排放的控制，评估由于海平面上升而产生的变化，并利用实地观察和实验开发综合控制这些环境甲烷排放的众多因素的模型。研究地点将位于路易斯安那州沿海地区，该地区占美国沿海受潮汐影响的淡水和咸水湿地的约40%，这些湿地的海平面上升率是世界上最高的。地球仪上有近10亿人生活在类似的沿海湿地附近，因此这项研究的结果将对解决大规模问题具有广泛的适用性。该项目的教育和推广活动将利用参与大学正在进行的项目，并进一步包括开发新的资源，将提供给学生和公众。拟议的时空框架将结合联合收割机现场，实验和基于模型的方法，以确定甲烷排放量从一系列设置（例如，海拔，盐度，距离水道，水文周期，温度，植被，土壤有机碳）和时间尺度（十年，百年，千年）在路易斯安那州沿海的Terrebonne-Timbalier河口。其中一些植被湿地土壤每年排放的甲烷比它们吸收的土壤碳还要多。 研究目标将：i）评估甲烷存量和排放的时空变化，ii）量化土壤和有机碳年龄和沉积历史，iii）确定不同时空尺度和跨地球化学梯度的土壤中的微生物和功能多样性，iv）实验性地评估由于洪水（例如，持续时间，频率，深度）制度的变化，v）整合景观变化到水动力学和生态地球化学模型，说明湿地配置和海平面的变化，iv）评估最佳数值参数，以模拟微生物-景观尺度的甲烷动态。本项目由地球科学前沿研究（FRES）计划，刺激竞争性研究的既定计划（EPSCoR），该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。