COLLABORATIVE RESEARCH: RAPID 2017 Hurricane Irma: How do the effects of pulse disturbance vary with abiotic conditions, disturbance history, and proximity to a transition zone.

风暴潮通常被认为是与飓风相关的对生命和财产的最大威胁。风暴潮对生态系统影响的研究往往集中在海滩等裸露的沿海地区。然而，咸水的上游输送可能会产生长期影响，并可能导致宝贵的淡水潮汐区域的衰落，这些区域为鱼类和野生动物提供栖息地，保护和改善水质，并储存洪水。鉴于由于海平面上升，上游咸水入侵，这些地区已经面临潜在的损失，这一点尤其重要。飓风伊尔玛于9月9日横扫美国。2017年11日，在佐治亚州中部海岸造成了有记录以来最高的风暴潮，导致咸水比往常上游移动了很多。由美国国家科学基金会赞助的佐治亚州海岸生态系统长期生态研究项目(GCE-LTER)有长期的实验和监测计划，提供“之前”的数据和了解这一事件的影响的背景。研究人员预计，风暴潮带来的咸水将影响潮间带湿地生态系统的多个组成部分，包括植物、动物、水化学和土壤表面海拔。这项研究的结果将通过佐治亚州海岸研究理事会和佐治亚州海岸灾害实践社区与沿海管理者分享。作为GCE校园计划的一部分，LTER的研究人员还将接待K-12教师，并与他们合作在课堂上使用这种经验。理解像飓风伊尔玛这样的干扰的影响是困难的，因为它们很难在实验中操纵，并且可能在不同的地貌部分表现不同。研究人员假设：1)风暴潮的影响将在上游地区比下游地区更大，其中潮汐淡水地点的影响最大，恢复时间最长；2)以前接触过咸水的地区将根据其历史表现出更大的影响；以及3)变化更有可能发生在不同湿地生境之间的地区(即盐沼和咸水沼泽植物之间的边缘)。他们将通过以下方式检验这些假设：1)增加GCE-LTER湿地监测点的样本，这些监测点沿佐治亚州中部海岸分布并向内陆延伸；2)利用正在进行的GCE-LTER野外实验，确定先前的盐分扰动处理如何影响对飓风风暴潮的反应；3)收集航空图像，使他们能够查看与风暴前地图相比植被类型的景观水平变化，并在预先确定的过渡地块中进行额外采样。LTER的研究人员推测，像这次风暴这样罕见但严重的事件是重新设定这些宝贵的潮间带湿地栖息地分布的主要场合。

Storm surge is often considered the greatest threat to life and property associated with a hurricane. Studies of the ecosystem effects of storm surge often focus on exposed coastal areas such as beaches. However, the upstream delivery of salt water can have long-lasting effects and can result in the decline of valuable freshwater tidal areas, which provide habitat to fish and wildlife, protect and improve water quality, and store floodwaters. This is especially important given the fact that these areas are already facing potential loss due to upstream salt water intrusion as a result of sea level rise. Hurricane Irma, which passed over the US on Sept. 11, 2017, caused the highest storm surge ever recorded on the central Georgia coast and resulted in salt water moving much further upstream than usual. The NSF-sponsored Georgia Coastal Ecosystems Long Term Ecological Research Project (GCE-LTER) has long-term experiments and monitoring programs that provide "before" data and a context for understanding the effects of this event. The investigators anticipate that the salt water delivered by the storm surge will affect multiple components of intertidal wetland ecosystems, including plants, animals, water chemistry, and soil surface elevation. The results of this research will be shared with coastal managers through the Georgia Coastal Research Council and the Georgia Coastal Hazards Community of Practice. The LTER researchers will also host K-12 teachers as part of the GCE Schoolyard Program and work with them to use this experience in the classroom.Understanding the effects of disturbances like Hurricane Irma is difficult because they are hard to manipulate experimentally and can act differently on different parts of the landscape. The investigators hypothesize that: 1) the effects of the storm surge will be greater in upstream as opposed to downstream areas, with the greatest effects and longest recovery times in tidal fresh sites; 2) areas that have had previous exposure to salt water will show greater effects based on their history; and 3) changes will be more likely in areas that are at the borders between different wetland habitats (i.e. the edge between salt marsh and brackish marsh plants). They will test these hypotheses by 1) augmenting sampling of the GCE-LTER wetland monitoring sites, which are distributed along and extend inland from the central Georgia Coast; 2) taking advantage of an ongoing GCE-LTER field experiment to determine how prior saline disturbance treatments affect responses to the hurricane storm surge; and 3) collecting aerial imagery that will allow them to look at landscape level shifts in vegetation type compared to pre-storm maps, and doing additional sampling in pre-established transitional plots. The LTER researchers speculate that rare but severe events like this storm are the major occasions that re-set the distribution of habitats in these valuable intertidal wetlands.