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: 1906622
• 负责人: Lauren Yeager
• 金额: $ 2.74万
• 依托单位: University of Texas at Austin
• 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 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1906622&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著特征。据估计，这些草地每年平均每公顷贡献20，000美元的商品和服务。这些措施包括营养循环，沉积物稳定，碳埋葬，并为幼鱼，螃蟹和虾提供育苗栖息地。令人担忧的是，海草受到几种环境和人为压力的威胁，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。在许多气候变化模拟情景下，风暴（频率和强度）和降雨量的预期增加使得了解飓风对宝贵的沿海栖息地（如海草草甸）的影响在地方，国家和全球范围内都很重要。事实上，海草草甸有可能作为“煤矿中的金丝雀”，因为它们被发现在较浅的深度，并受到浊度和盐度的影响，增加飓风活动的影响;海草也容易受到埋葬或侵蚀，由于大风暴。海草（1）包括一套具有不同生长和繁殖策略的物种;（2）生活在一系列草甸大小和“斑块”程度的范围内;（3）呈现不同的季节周期。这是一个巨大的机会，可以探索导致海草对飓风的复原力或脆弱性的条件和属性，作为更广泛的沿海生态系统对策的模型。 飓风佛罗伦萨于2018年9月14日沿着北卡罗来纳州海岸登陆。佛罗伦萨在接近海岸时停止前进，北卡罗来纳州东南部的风暴相关风雨持续了4天（13日至16日）。随后，整个北卡罗来纳州海岸线观测到创纪录的高海平面（浪涌+潮汐）。此外，佛罗伦萨成为美国第二潮湿的风暴，仅次于2017年的哈维，在陆地上倾倒了65万亿L的雨水，使河口盐度下降了一个多月。NC海草主要由三个物种组成：鳗草，草和野生草。草地以混合栽培或单一栽培的形式存在，并表现出多种多样的空间配置。草甸也被定义为强烈的季节性：由于热应力，夏天鳗鱼草芽衰老，场地转变为以浅滩为主的草甸或泥滩。枯死后，每年冬天，鳗草依靠种子库和存活的顶端分生组织的组合进行再生。 使用研究小组收集的关键海草数据集，这些数据集可以追溯到几十年前，跨越约40个受佛罗伦萨影响的草地，解决了几个基本的生态问题：（1）性（eelgrass：seedbank）v.无性的生活史促进海草对干扰的敏感性或恢复力;（2）草甸景观格局和植物多样性如何调节风暴对种子库保留的影响;（3）草地干扰（强烈的物理驱动因素与更慢性的生理化学驱动因素）影响了群落动态，特别关注植物生产力和海草栖息地的关键“苗圃作用”;以及（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。这项研究扩大了以前的飓风后的研究，考虑飓风，景观配置和生物多样性对生态系统响应的相互作用。它还利用正在进行的，NSF支持的工作沿着德克萨斯州海岸比较和对比不同的海草物候/生长策略对风暴干扰的反应（例如，在德克萨斯州的龟草是一种全年都是“长叶”的物种，而在北卡罗来纳州的鳗草和浅滩草都表现出生物量的强烈季节性。总的来说，这项工作将导致更普遍的沿海生态恢复模型，以storminess.This奖项反映了NSF的法定使命，并已被认为是值得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的支持。