Coupled Ecological-Geomorphological Response of Coastal Wetlands to Environmental Change

沿海湿地与整个地貌系统链相连，从大陆内陆的泥沙和径流产生区，到山前和泛滥平原地区，再到海岸附近的海洋系统。因此，沿海湿地动态与各种地球表面系统密切相关，并对明显偏远和互不相连的地区发生的各种环境变化作出反应。事实上，滨海湿地对大量驱动力的变化很敏感，包括河流沉积物输送速率、海平面上升速率、下沉速率、波浪气候，以及通过植物产生的有机沉积物对营养物质浓度、温度和大气二氧化碳浓度的变化。此外，直到最近才对沿海湿地的碳储量和单位面积的碳埋藏率进行了量化，发现它们是所有生物群中最高的，因此是全球碳循环中的主要参与者。尽管它们对环境变化很敏感，在全球地球系统中也很重要，但仍然缺乏对湿地动态的预测性了解，包括植被、潮汐水道网络、潮滩和永久淹没区域。这个项目将对研究、教育和社会产生影响。考虑到受威胁湿地的生态系统服务，以及海岸附近的大量人口将受到湿地面积变化的影响，拟议工作的结果显然具有社会重要性。结果将提供海岸地貌、生态系统模式和碳埋藏率变化的同步估计。多个层次的学生(本科生、专业硕士、博士)将受到该项目教育/推广计划的影响，其中包括新的和改进的课程以及实地经验。该项目的影响将通过以下方式加强：1)与生命与科学博物馆(北卡罗来纳州达勒姆)建立实质性伙伴关系，以提高对环境变化的认识，以K-12和普通成人观众为目标，包括沿海地区的观众，提供实践活动、课程材料和纪录片；和2)与威尼斯泻湖渡轮服务公司Alilagouna合作，向任何对威尼斯泻湖及其未来感兴趣的人传播项目背景和研究结果。该项目的智力优势在于开发、测试和提供新的遥感方法来观察从单一湿地尺度到次区域尺度的海岸地貌和生态模式，从而更好地理解不同环境变化模式对湿地生存的相对重要性，澄清海岸系统对变化强迫的反应是否(或在什么情况下)可能是渐进的还是突然的。该项目将生成和比较两个系统-一个代表美国东海岸湿地区域(南卡罗来纳州北湾)和一个典型地中海泻湖(意大利威尼斯)-对全球沿海地区的影响，并比较海岸对预期环境变化的反应情景，特别关注碳埋藏率和碳循环的变化。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。

Coastal wetlands are connected with an entire chain of geomorphic systems, from the sediment- and runoff- generating areas in the continental interior, to piedmont and floodplain areas, to the marine systems near the coast. As a result, coastal wetland dynamics are strongly coupled with a wide variety of Earth's surface systems and respond to a wide range of environmental changes taking place in apparently remote and unconnected areas. In fact, coastal wetlands are sensitive to changes in a large number of forcings, including fluvial sediment delivery rates, rates of sea level rise, subsidence rates, wave climate, and, via organic sediment production by plants, to changes in nutrient concentrations, temperature, and atmospheric CO2 concentration. Furthermore, only recently have the carbon storage and the rate of carbon burial per unit area been quantified in coastal wetlands, to find that they are the highest of any biome and thus major players in the global carbon cycle. Despite their sensitivity to environmental change and their importance in the global Earth system, a predictive understanding of wetland dynamics coupled with vegetation, the tidal channel network, the tidal flats, and the permanently submerged areas is still missing. This project will impact research, education, and society. Given the ecosystem services of threatened wetlands, and the large human population near the coast that will be affected by changes in wetland area, the results of the proposed work are of clear societal importance. The results will provide simultaneous estimates of changes in coastal geomorphology, ecosystem patterns, and carbon burial rates. Students at multiple levels (undergraduate, professional master, PhD) will be impacted by the project's education/outreach plans, which include new and enhanced coursework, and field experiences. The impact of the project will be enhanced through: 1) a substantial partnership with the Museum of Life and Science (Durham, NC), to increase the awareness of environmental change, targeting K-12 and the general adult audiences including those at the coast with hands-on activities, curricular material, and a documentary; and 2) a partnership with the Venice Lagoon ferry service Alilaguna, to disseminate project background and findings to anyone interested in the Venice Lagoon and its future.The intellectual merit of the project lies in developing, testing, and making available new remote sensing methods to observe coastal geomorphological and ecological patterns, from the single wetland scale to the sub-regional scale, in an improved understanding of the relative importance of different modes of environmental change for wetland survival, clarifying whether (or under what circumstances) coastal system response to changing forcing is likely to be gradual versus sudden. The project will generate and compare scenarios of coastal responses to expected environmental changes for two systems—one representative of wetland areas in the US eastern seaboard (North Inlet, SC), and one typical Mediterranean lagoon (Venice, Italy)—with implications for coastal zones globally, with particular attention to changes in rates of carbon burial and the carbon cycle.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.