RAPID: COLLABORATIVE RESEARCH: Mechanisms of seagrass community injury and resilience post Hurricane Florence: implications for increasingly stormy coasts

快速：合作研究：佛罗伦萨飓风后海草群落损伤和恢复力的机制：对日益暴风雨海岸的影响

• 批准号: 1906635
• 负责人: Jessie Jarvis
• 金额: $ 9万
• 依托单位: University of North Carolina at Wilmington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1906635&HistoricalAwards=false
• 关键词: RAPID; COLLABORATIVE; RESEARCH; Mechanisms; seagrass

Seagrass meadows are conspicuous features of many estuarine and nearshore environments. By some estimates, these meadows contribute an average of $20,000 per hectare per year in goods and services. These include nutrient cycling, sediment stabilization, carbon burial, and provision of nursery habitat for juvenile fishes, crabs, and shrimps. Alarmingly, seagrasses are threatened by several environmental and human-driven stressors, and loss of seagrass habitat remains a key concern for conservation and sustainable development programs. Anticipated increases in storminess (frequency and intensity) and rainfall under many climate change modeling scenarios make understanding hurricane impacts on valuable coastal habitats such as seagrass meadows important on local, national, and global scales. Indeed, seagrass meadows potentially serve as a 'canary in the coal mine' regarding the effects of increased hurricane activity as they are found at shallow depths and are affected by turbidity and salinity; seagrasses are also vulnerable to burial or erosion due to large storms. Seagrasses (1) include a suite of species with distinct growth and reproductive strategies; (2) live in a range of meadow sizes and degrees of 'patchiness;' and (3) present divergent seasonal cycles. This represents a tremendous opportunity to explore the conditions and attributes that result in seagrass resilience or vulnerability to hurricanes as a model for coastal ecosystem responses more broadly. Hurricane Florence made landfall along the NC coast on September 14, 2018. Florence stalled approaching shore, and storm-related winds/rains persisted for 4 days (13th-16th) in southeastern NC. Subsequently, record high sea-level stands (surge + tide) were observed across the NC coastline. Furthermore, Florence became the second wettest US storm, behind only Harvey in 2017, dumping 65 trillion L of rain over land that depressed estuarine salinities for over a month. NC seagrasses are dominated by three species: eelgrass, shoalgrass, and widgeon grass. Meadows exist as polycultures or monocultures, and exhibit a diverse range of spatial configurations. Meadows are also defined by strong seasonality: eelgrass shoots senesce in summer due to heat stress, with sites transformed either into shoalgrass-dominated meadows or mudflats. Subsequent to dieback, eelgrass depends upon a combination of seedbank and surviving apical meristems for regeneration each winter. Using key seagrass datasets collected by the research team dating back decades across ~40 Florence-impacted meadows, several fundamental ecological questions are being addressed: (1) how sexual (eelgrass: seedbank) v. asexual (shoalgrass: vegetative growth and fragment colonization) life histories promote susceptibility or resilience of seagrass to disturbance; (2) how meadow landscape configuration and plant diversity modulate the effect of storms on seedbank retention; (3) how meadow disturbance (intense physical v. more chronic physiochemical drivers) affected community dynamics, with special focus on plant productivity and the critical 'nursery role' of seagrass habitat; and (4) how seasonality and species traits amplify or attenuate the effects of intense disturbance on seagrasses. This research expands upon previous post-hurricane studies by considering the interactive effects of hurricanes, landscape configuration, and biodiversity on ecosystem responses. It also leverages ongoing, NSF-supported work along the TX coast to compare-and-contrast the responses of different seagrass phenology/growth strategies to storm disturbance (e.g., turtlegrass in TX is a "leaf-on" species throughout the year while eelgrass and shoalgrass in NC both exhibit strong seasonality in biomass). Collectively, this work will result in more generalizable models of coastal ecological resilience to storminess.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.

海草草甸是许多河口和近岸环境的显着特征。据估计，这些草地每年每公顷平均贡献 20,000 美元的商品和服务。其中包括养分循环、沉积物稳定、碳埋藏以及为幼鱼、螃蟹和虾提供苗圃栖息地。令人担忧的是，海草受到多种环境和人类驱动的压力源的威胁，海草栖息地的丧失仍然是保护和可持续发展计划的一个关键问题。在许多气候变化建模情景下，预计暴风雨（频率和强度）和降雨量将增加，这使得了解飓风对海草草甸等宝贵沿海栖息地的影响在地方、国家和全球范围内变得非常重要。事实上，在飓风活动增加的影响方面，海草草甸有可能成为“煤矿里的金丝雀”，因为它们位于浅层深处，并受到浑浊度和盐度的影响；海草也容易因大风暴而被掩埋或侵蚀。海草 (1) 包括一系列具有独特生长和繁殖策略的物种； (2) 生活在各种大小和“斑驳程度”的草地中； (3)呈现不同的季节周期。这是一个巨大的机会，可以探索导致海草恢复力或飓风脆弱性的条件和属性，作为更广泛的沿海生态系统响应的模型。 飓风“佛罗伦斯”于 2018 年 9 月 14 日在北卡罗来纳州海岸登陆。“佛罗伦斯”飓风接近海岸时停滞，北卡罗来纳州东南部与风暴相关的风/雨持续了 4 天（13 日至 16 日）。随后，北卡罗来纳州海岸线出现了创纪录的高海平面（海浪+潮汐）。此外，佛罗伦萨成为美国第二大潮湿风暴，仅次于 2017 年的哈维，给陆地带来了 65 万亿升的降雨，导致河口盐度下降了一个多月。北卡罗来纳州海草主要由三个物种组成：鳗草、浅滩草和威吉恩草。草地以多种栽培或单一栽培的形式存在，并表现出多种空间配置。草甸也具有强烈的季节性：由于热应激，鳗草芽在夏季衰老，场地变成以浅滩草为主的草甸或泥滩。在枯死之后，鳗草每年冬天依靠种子库和幸存的顶端分生组织的结合来再生。 利用研究小组在约 40 个受佛罗伦萨影响的草地上收集的关键海草数据集，可以追溯到几十年前，几个基本的生态问题正在得到解决：（1）有性（鳗草：种子库）与无性（浅滩草：营养生长和碎片定植）生活史如何提高海草对干扰的敏感性或恢复力； (2) 草甸景观配置和植物多样性如何调节风暴对种子库保留的影响； （3）草甸干扰（强烈的物理驱动因素与更长期的物理化学驱动因素）如何影响群落动态，特别关注植物生产力和海草栖息地的关键“苗圃作用”； （4）季节性和物种特征如何放大或减弱强烈干扰对海草的影响。这项研究在之前的飓风后研究的基础上进行了扩展，考虑了飓风、景观配置和生物多样性对生态系统响应的交互影响。它还利用德克萨斯州海岸正在进行的、由国家科学基金会支持的工作来比较和对比不同海草物候/生长策略对风暴扰动的响应（例如，德克萨斯州的海龟草是全年“叶生”物种，而北卡罗来纳州的鳗草和浅滩草都在生物量方面表现出很强的季节性）。总的来说，这项工作将产生更通用的沿海生态风暴恢复力模型。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。