Resilience of a coastal ecosystem following hurricane Irma

珊瑚礁、盐沼和沙丘等沿海生态系统处于气候变化的最前线。一方面，这些自然系统越来越多地被要求保护人们和财产免受风暴和飓风的影响，这些风暴和飓风在气候变化下变得更加强烈。另一方面，这些系统本身也受到了伴随着最强风暴的强大而破坏性的风暴潮和海浪的威胁。因此，在经历了一场大风暴后，沿海生态系统能够以多快的速度和多大的程度恢复(显示出韧性)，并恢复保护我们的海岸线，这成为一个相关的问题，特别是考虑到2017年高度活跃和破坏性的大西洋飓风季节。其中一个这样的风暴，飓风伊尔玛，在9月10日和11日给佛罗里达州西南部和东部以及佐治亚州和南卡罗来纳州海岸带来了巨大的风暴潮。沙丘是该地区和世界其他许多地区的一条重要和广泛的海岸防线，遭到广泛侵蚀，许多地区的关键沙丘被完全摧毁。受影响的沙丘横跨城市和偏远、未开发的地区以及植物组成存在差异的地区(东海岸和西海岸)，为调查控制这些生态系统反弹能力的因素提供了独特的机会。这项研究将讨论植物功能多样性(或植物生存、生长和繁殖方式的变化)在决定沙丘恢复中的作用。由于功能的不同将允许不同物种以不同的方式应对风暴影响(例如，从根部重新生长，或从种子重新生长)，并在不同的时间利用海滩的不同部分，因此更多种类的植物有望促进恢复。该项目还将解决城市发展对沙丘恢复的影响，这是沿海规划中的一个关键问题。此外，它还将调查一个关键的管理问题--被冲刷的植物和碎片如何影响沙丘的恢复，以及它们在清理工作中的清除是否可能减缓恢复？为了回答这些问题，我们将在24个地点进行大规模调查，测量植物的多样性，跟踪单个植物的命运和生长，并记录2018年3次野外考察期间植被和沙丘形态(以及海岸保护)的恢复情况。为了更好地了解垃圾和被冲上海岸的植物的作用，我们将在野外实验中将这些碎片从重复的斑块中移除，跟踪沉积物和植物群落在一年中的变化，并使用现代统计技术来揭示任何影响(增加营养物质、沉积、缓冲高温？)是被调停的。我们预计这些研究将：1)阐明植被功能多样性在沙丘恢复中的作用；2)揭示自然地点的植被恢复如何受到碎屑和枯死植物材料的影响，以及这些过程可能如何从高度管理的地点消失；3)提供一个罕见的案例研究，说明生物多样性在为人们提供可靠和有弹性的利益方面的重要性。

Coastal ecosystems like coral reefs, salt marshes and sand dunes are at the front line of climate change. On the one hand, these natural systems are increasingly called upon to shield people and properties from storms and hurricanes which are growing more intense under climate change. On the other hand, these same systems are themselves threatened by the powerful and destructive storm surges and waves that accompany the strongest storms. How fast - and how completely - coastal ecosystems can bounce back (show resilience) after a major storm, and return to shielding our shorelines, therefore becomes a pertinent question, particularly in light of the highly active and damaging Atlantic hurricane season of 2017. One such storm, hurricane Irma, brought a large storm surge to southwestern and eastern Florida, as well as to the coasts of Georgia and South Carolina, on the 10th and 11th of September. Sand dunes, an important and extensive line of coastal defence in that region and many others worldwide, suffered widespread erosion, with crucial foredunes completely wiped out in many areas. Affected dunes span urban and remote, undeveloped, areas and regions with differences in plant composition (east vs. west coast), providing a unique opportunity to investigate factors that control the ability of these ecosystems to rebound. This study will address the role of plant functional diversity (or variation in the way plants survive, grow and reproduce) in determining dune recovery. Because differences in function will allow different species to respond to the storm impacts in contrasting ways (e.g., re-growing from roots, or re-establishing from seeds) and use different parts of the beach at different times, a greater variety of plants is expected to boost recovery. This project will also address the effects of urban development in sand dune recovery, a key issue in coastal planning. And further, it will investigate a critical management issue - (how) do washed-up plants and debris affect sand dune recovery, and does their removal in cleanup efforts potentially slow recovery? To answer these questions we will do large-scale surveys spanning 24 sites, measure the diversity of plants, track the fate and growth of individual plants, and record the recovery of vegetation and dune morphology (and so coastal protection) during 3 field expeditions in 2018. To better understand the role of debris and washed up coastal plants, we will remove these from replicated patches in a field experiment, track sediment and plant community changes over the year, and use modern statistical techniques to reveal how any effects (increased nutrients, sedimentation, buffering high temperatures?) are mediated. We anticipate that these studies will: 1) illuminate the role of vegetation functional diversity in sand dune recovery; 2) reveal how vegetation recovery is affected by debris and dead plant material at a natural site, and how these processes might be lost from highly managed sites; and 3) provide a rare case study on the importance of biodiversity in providing reliable and resilient benefits to people.