RAPID proposal: Impact of storm surge on coastal forest demography in response to repeated hurricane disturbances

不常发生的大扰动，如飓风，通过风暴潮带来的破坏性风和咸水，极大地改变了沿海森林。根据飓风的频率以及风害和盐水入侵的同时程度，沿海森林可能受到严重破坏，并可能转变为盐水沼泽。随着气候系统的变化，飓风的回归时间将减少，预计海平面上升将增加盐入侵的机会。目前对飓风影响的理解主要是基于单一飓风的影响；很少有研究记录在一个地方反复出现的风暴的影响，或者将风暴潮的影响与风的影响分开。2016年10月，飓风马修袭击了南卡罗来纳海岸，在很大程度上与1989年飓风雨果影响的地区相同，从而为研究多次飓风对同一沿海森林的影响提供了机会。飓风马修的强度和被海水淹没的地区有所不同。该项目将引进较新的遥感能力，以扩大研究范围，了解受影响森林结构和功能的短期和长期影响，以及在更大的景观和区域尺度上的影响。该项目对风害、盐胁迫、土壤化学、树木功能和树木建立的及时实地评估与遥感相结合，将检验理论预测，并促进对沿海森林罕见大干扰的了解。大而不频繁的干扰可能在很长一段时间内构成森林生态系统的响应，并可能触发阈值响应，导致生态系统响应的多种路径，甚至整个生态系统结构和功能的转移。许多关于飓风扰动对沿海森林生态系统影响的理论都是来自于对单一飓风或飓风后的即时反应的研究。为了充分了解飓风的恢复和变化轨迹，需要在短时间和长时间、地点到区域的空间尺度上对多次飓风进行实证测试和数据评估。该项目利用沿海生态系统长期实地研究的数据和研究地点，研究雨果飓风对从风投和盐胁迫中恢复的影响。新的研究将研究飓风马修的风害和盐入侵如何影响土壤过程、森林死亡率和演替、森林功能和非本地物种的入侵，以应对不同的飓风干扰。遥感将评估整个沼泽/森林景观和南卡罗来纳海岸多个研究区域的森林结构、压力、物候和植物特征。这项工作将为扰动理论、演替、生态系统结构和功能在多个空间和时间尺度上的应用提供重要的检验。

Large infrequent disturbances, such as hurricanes, significantly alter coastal forests through damaging winds and salt water carried with the storm surge. Depending on the frequency of the hurricanes and concurrent extent of the wind damage and salt water intrusion, coastal forests can be significantly damaged and may transition into salt water marsh. With a more variable climate system, hurricane return times will decrease and projected increasing sea level rise will enhance the opportunity for salt intrusion. Current understanding of hurricane effects is based largely on the effects of a single hurricane; few studies exist that document effects of repeated storms in one location or that separate the effects of storm surge from wind. In October 2016 Hurricane Matthew hit the South Carolina coast in largely in the same area affected by Hurricane Hugo in 1989, thus providing an opportunity to study multiple hurricane impacts on the same coastal forests. Hurricane Matthew differed in intensity and areas inundated with salt water. The project will introduce newer remote sensing capabilities to expand the studies to understand the short term and long term impacts on structure and functioning of the affected forests and at larger landscape and regional scales. This project's timely field assessments of wind damage, salt stress, soil chemistry, tree functioning, and tree establishment coupled with the remote sensing will test theoretical predictions and advance understanding of large infrequent disturbances on coastal forests. Large infrequent disturbances may structure forest ecosystem responses for very long periods of time and may trigger threshold responses that cause multiple paths of ecosystem response or even shifts in complete ecosystem structure and function. Much of the theory devoted to hurricane disturbance effects on coastal forest ecosystems arises from the study of single hurricanes or immediate response following the hurricane. Empirical tests and data are needed to evaluate multiple hurricanes across short and long time and site to regional space scales to fully understand the recovery and trajectories of change. This project leverages data and research sites from a long-term field study of coastal ecosystems to examine the consequences of the Hurricane Hugo on the recovery from wind throw and salt stress. The new studies will examine how wind damage and the salt intrusion from Hurricane Matthew affected soil processes, forest mortality and succession, forest functioning, and invasion of non-native species in response to differential hurricane disturbance. The remote sensing will assess forest structure, stress, phenology, and plant traits across the marsh/forest landscape and at multiple study areas along the coast of South Carolina. This work will provide critical tests of disturbance theory, succession, ecosystem structure and function across multiple space and time scales.