Investigation of Wetland Biogeochemical Similitudes and Scaling for Robust Predictions of Greenhouse Gas Emissions and Carbon Sequestration

1336911(阿卜杜勒-阿齐兹)。本研究的目的是：(i)调查和揭示湿地温室气体（GHG）排放和碳固存的相似性（参数减少）、时空尺度模式和不同环境制度；（ii）建立时空稳健的模型，用于预测不同气候、水文、生物、生态和生物地球化学梯度下的湿地温室气体排放和碳固存。本文将通过量纲分析和经验模型验证湿地温室气体排放和碳固存的基本假设，该假设遵循不同的生物地球化学相似性和稳健的尺度关系，该假设已成功应用于流体力学、水利工程和河流生物地球化学/生态学。尺度关系的稳健性将首先通过推导解析性的、真正动态的灵敏度系数和不确定性度量来确定，并用现场数据对它们进行量化。尺度稳健性还将通过比较来自不同季节和地点的数据估计的尺度参数（系数和指数）来评估，这些数据代表了水文气候、生物地球化学和生态过程的梯度。本研究主要利用PI的主要湿地温室气体（CO2， CH4和N2O）和环境参数的现场数据收集，模型开发和知识形成，这些数据正在由美国国家海洋和大气管理局（NOAA）资助的一个合作项目中进行。它还利用了湿地生物地球化学和温室气体通量数据，这些数据是由其他合作者通过美国东海岸的室内实地活动收集的。研究目标是建立湿地生物地球化学涌现（相似）模式的基本知识体系，识别不同的环境制度和相关的温室气体排放和碳封存过渡阈值。湿地温室气体排放的建模一直是一项极具挑战性的工作。现有的模型在本质上大多是机械的和特定地点的，往往不能提供在时间和空间上相对可靠的预测。为了应对这一挑战，我们将采用在地球科学和工程的其他分支中成功应用的分析和经验方法来研究湿地的生物地球化学相似性和标度规律。在气候、海平面和土地利用变化的背景下，提高对相似度和尺度的理解，有望对不同湿地生态系统的温室气体排放和碳固存进行稳健、简洁的建模和预测。生物地球化学相似度和标度的研究有望为整个生态系统的碳动力学提供新的见解。这个想法可能适用于识别、理解和预测陆地和海洋生态系统的碳固存和温室气体排放的稳定模式。通过揭示基础科学信息和提供规模无关的工程工具，该研究将有助于全球湿地生态系统的碳管理。研究成果将通过同行评议的出版物、演讲、讲习班、报告、公开会议、公开媒体（如YouTube）广泛传播；并通过利用PI目前与NOAA合作的湿地科学家、工程师、经济学家、保护区管理者、利益相关者和非政府组织组成的项目团队，转移给沿海决策者。研究结果将通过在FIU（一所拥有约59%西班牙裔/拉丁裔学生和13%非裔美国学生的大型少数民族大学）设计以归纳学习为基础的研究生和本科课程，并让高中教师和学生参与进来，从而纳入教育。这项研究为国际金融大学的一名在读博士生和一名潜在的少数民族本科生暑期实习生提供补充资金。

1336911 (Abdul-Aziz). The objectives of this research are to (i) investigate and unravel similitudes (parametric reductions), spatiotemporal scaling patterns, and different environmental regimes of wetland greenhouse gas (GHG) emissions and carbon sequestrations; and (ii) formulate spatiotemporally robust models for predicting wetland GHG emissions and carbon sequestration across different climatic, hydrologic, biological, ecological, and biogeochemical gradients. A fundamental hypothesis of wetland GHG emissions and carbon sequestration following distinct biogeochemical similitudes and robust scaling relationships will be tested by conducting dimensional analysis and empirical modeling, which has successfully been applied in fluid mechanics, hydraulic engineering, and stream biogeochemistry/ecology. Robustness of the scaling relationships will first be determined by deriving analytical, truly dynamic sensitivity coefficients and uncertainty measures and quantifying them with field data. Scaling robustness will also be evaluated by comparing scaling parameters (coefficients and exponents) estimated with data from different seasons and locations representing a gradient of hydro-climatic, biogeochemical, and ecological processes. This research primarily leverages the PI's field data collections for major wetland GHGs (CO2, CH4, and N2O) and environmental parameters, model developments, and knowledge formation underway in a collaborative project funded by the National Oceanic and Atmospheric Administration (NOAA). It also utilizes wetland biogeochemistry and GHG flux data collected by other collaborators through chamber-based field campaigns across the U.S. East Coast. The research targets to generate a fundamental body of knowledge and insights into the wetland biogeochemical emergence (similarity) patterns, identifying different environmental regimes and associated transition thresholds of GHG emissions and carbon sequestrations. Modeling of wetland GHG emissions has been an extremely challenging undertaking. Available models are mostly mechanistic and site-specific in nature, often failing to provide predictions that are relatively robust in time and space. To address this challenge, wetland biogeochemical similitudes and scaling laws will be investigated by employing analytical and empirical methods successfully applied in other branches of earth sciences and engineering. Improved understanding of similitudes and scaling is expected to lead to robust, parsimonious modeling and predictions of GHG emissions and carbon sequestration from diverse wetland ecosystems under a changing climate, sea level, and land use. The research on biogeochemical similitudes and scaling is anticipated to provide new insights into overall ecosystem carbon dynamics. The idea is potentially applicable to identify, understand, and predict robust patterns of carbon sequestration and GHG emissions from the terrestrial and marine ecosystems. The research should aid carbon management in wetland ecosystems around the world by unraveling fundamental scientific information and providing scale-independent engineering tools. Research outcomes will be broadly disseminated through peer-reviewed publications, presentations, workshops, reports, public meetings, open media (e.g., YouTube); and transferred to the coastal decision makers by leveraging the PI's current NOAA collaborative project-team of wetland scientists, engineers, economists, reserve managers, stakeholders, and NGOs. The research findings will be incorporated into education by designing inductive learning-based graduate and undergraduate courses at FIU (a large minority institution with around 59% Hispanic/Latino and 13% African-American students) and involving high school teachers and students. The research provides complementary funding for a current doctoral student at FIU and a potential undergraduate summer intern from the minority students.