Coastal SEES Collaborative Research: A cross-site comparison of salt marsh persistence in response to sea-level rise and feedbacks from social adaptations

世界上近一半的人口生活在距离海岸100公里的范围内，该地区被列为最容易受到气候驱动的海平面上升(SLR)影响的地区。预计SLR的加速速度将导致巨大的变化，从而改变低洼沿海地区的生态和社会动态。因此，面对可持续发展问题，必须更好地了解沿海人-环境耦合系统的可持续性。盐沼是潮间带生境，为沿海社区提供了对SLR的缓冲，也具有许多其他生态系统服务的价值，包括野生动物栖息地、营养循环、碳固存、美学和旅游业。它们是高度动态的系统，几千年来一直与海平面的变化保持同步。然而，预计SLR的比率，以及沿海流域和海岸线更多的人为改造，可能会将沼泽推过一个临界点，超过这个临界点，它们就会消失。开发沼泽脆弱性的现实情景需要一种综合的方法来理解影响沼泽持久性及其支持功能的生物物理和社会因素之间的反馈。该项目将研究美国大西洋沿岸三个地点的盐沼对SLR的相对脆弱性，这些地点在沉积物供应、潮差和人类影响方面存在差异。研究小组还将研究潜在适应的反馈如何影响湿地脆弱性、相关的经济利益和成本以及实际管理决策。其他更广泛的影响包括将研究成果纳入当地学校使用的课程、在线跨学科研究生课程和正在进行的教师培训计划，以及培训一名博士后研究员、四名研究生和八名本科生研究人员。该项目作为国家科学基金会海岸科学、工程和可持续发展教育计划-海岸可持续发展计划的一部分得到支持。该项目利用了三个大西洋海岸长期生态研究地点(位于马萨诸塞州、弗吉尼亚州、佐治亚州)的长期数据、实验和建模工具，并解决了广泛的跨学科问题：沼泽对SLR的反应和人类对潜在沼泽丧失的适应之间的反馈将如何影响组合的社会生态系统的整体可持续性？该项目的目标是了解：1)在有和没有适应行动的情况下，沼泽对当前和预计的单反的脆弱性如何在生物地理省份和一系列生物物理和社会驱动因素之间进行比较；以及2)当地利益攸关方团体更喜欢哪些沼泽保护行动，以及可行的适应方案的更广泛的可持续性和经济价值影响。生物物理研究使用历史趋势、“点”和空间模型来确定沼泽对SLR的阈值和长期响应。通过与利益攸关方进行未来情景规划，对沼泽适应备选方案进行经济评估，以及重点小组将合并的项目成果置于具体的政策规划背景下，以评估沼泽如何适应沿海社会生态可持续性的更广泛视角，将对沼泽脆弱性的社会反应与生物物理模型相结合。按照环境和人类驱动因素的梯度在多个地点采取这种综合办法，将使人们能够就人与自然系统的相互作用和可持续性作出一般性结论，这些结论可广泛适用于其他沿海系统。

Nearly half of the world's population lives within 100 km of the coast, the area ranked as the most vulnerable to climate-driven sea-level rise (SLR). Projected rates of accelerated SLR are expected to cause massive changes that would transform both the ecological and social dynamics of low-lying coastal areas. It is thus essential to improve understanding of the sustainability of coupled coastal human-environment systems in the face of SLR. Salt marshes are intertidal habitats that provide a buffer for coastal communities to SLR and are also valued for many other ecosystem services, including wildlife habitat, nutrient cycling, carbon sequestration, aesthetics, and tourism. They are highly dynamic systems that have kept pace with changes in sea level over millennia. However, projected rates of SLR and increased human modification of coastal watersheds and shorelines may push marshes past a tipping point beyond which they are lost. Developing realistic scenarios of marsh vulnerability demands an integrated approach to understanding the feedbacks between the biophysical and social factors that influence the persistence of marshes and their supporting functions. This project will examine the comparative vulnerability of salt marshes to SLR in three U.S. Atlantic coastal sites that vary with respect to sediment supply, tidal range and human impacts. The research team will also address how feedbacks from potential adaptations influence marsh vulnerability, associated economic benefits and costs, and practical management decisions. Additional broader impacts include incorporating research results into curriculum used at local schools, an on-line cross-disciplinary graduate course, and on-going teacher-training programs, as well as training one postdoctoral researcher, four graduate students, and eight undergraduate researchers. This project is supported as part of the National Science Foundation's Coastal Science, Engineering, and Education for Sustainability program - Coastal SEES.This project leverages the long-term data, experiments and modeling tools at three Atlantic Coast Long-Term Ecological Research sites (in MA, VA, GA), and addresses the broad interdisciplinary question "How will feedbacks between marsh response to SLR and human adaptation responses to potential marsh loss affect the overall sustainability of the combined socio-ecological systems?" The goals of the project are to understand: 1) how marsh vulnerability to current and projected SLR, with and without adaptation actions, compares across biogeographic provinces and a range of biophysical and social drivers; and 2) which marsh protection actions local stakeholder groups favor, and the broader sustainability and economic value implications of feasible adaptation options. The biophysical research uses historical trends, "point" and spatial models to determine threshold and long-term responses of marshes to SLR. Social responses to marsh vulnerability are integrated with biophysical models through future scenario planning with stakeholders, economic valuation of marsh adaptation options, and focus groups that place the combined project results within a concrete policy planning context to assess how marshes fit into the larger view of coastal socio-ecological sustainability. This integrated approach at multiple sites along gradients of both environmental and human drivers will allow for general conclusions to be made about human-natural system interactions and sustainability that can be broadly applicable to other coastal systems.