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: 2218581
• 负责人: Brian Roberts
• 金额: $ 94.49万
• 依托单位: Louisiana Universities Marine Corsortium
• 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=2218581&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(CH4)是一种气体，尽管它在大气中的浓度比二氧化碳(CO2)低得多，但它具有更强大的温室效应，可能占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缓解气候变化产生快速而深远的效果。尽管人为来源减少，但大气中甲烷的数量仍在增加；因此，必须准确评估自然环境中甲烷的生产过程。沿海湿地约占全球甲烷排放量的40%，由于海平面上升、沉积物堆积、生态变化和景观动态，这些地区处于不断变化中。该项目将调查目前对沿海湿地甲烷排放的控制，评估其因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，那里拥有美国约40%的沿海、受潮汐影响的淡水和咸水湿地，这些湿地的相对海平面上升速度是世界上最高的。全球有近10亿人居住在类似的滨海湿地附近，因此这项研究成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计划，并进一步包括开发新的资源，供学生和公众使用。拟议的时空框架将结合现场、实验和基于模型的方法，以确定路易斯安那州沿海特雷博内-廷巴利耶河口一系列环境(例如，海拔、盐度、距离水道、水文时期、温度、植被、土壤有机碳)和时间尺度(十年-百年-千年)的甲烷排放量。其中一些植被覆盖的湿地土壤每年排放的甲烷比它们固定的土壤碳更多。研究目标将：i)评估甲烷库存和排放的时空变异性，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微生物和功能多样性，iv)通过实验评估洪水引起的甲烷通量(例如，持续时间、频率、深度)制度变化，v)将景观变化整合到考虑湿地形态和海平面变化的水动力和生物地球化学模型中，以及iv)评估最佳数值参数以模拟微生物-景观尺度上的甲烷动态。该项目由地球科学前沿研究(FRES)计划共同资助，已建立的激励竞争研究计划(EPSCoR)和环境生物学部门(DEB)的生态系统科学计划。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。