Collaborative Research: RAPID: Quantifying mechanisms by which Hurricane Michael facilitates a stable-state reversal on oyster reefs

合作研究：RAPID：量化迈克尔飓风促进牡蛎礁稳定状态逆转的机制

基本信息

批准号：
1916870
负责人：
James White
金额：
$ 2.98万
依托单位：
Oregon State University
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：
2019-02-15 至 2020-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1916870&HistoricalAwards=false
关键词：
Collaborative Research RAPID Quantifying mechanisms

项目摘要

Ecosystems can exhibit "tipping points" whereby an environmental disturbance pushes an ecosystem into an altered state from which it does not recover, even when the environment normalizes. This may have happened to valuable oyster reefs in Northwest Florida in 2012, when drought and low river flow allowed predators of oysters to flourish and consume nearly all the oysters. Despite subsequent years of normal rainfall and river flow, oysters have not recovered, suggesting the ecosystem may have crossed a tipping point. However, the timing and magnitude of the disturbance from Hurricane Michael (2018) may have pushed the ecosystem back towards its original, healthy state. In this project, investigators make field observations to gauge how predators and oysters are responding to Hurricane Michael and conduct lab experiments to test how predators and oysters respond to hurricane rainfall conditions. Additionally, they use mathematical models to predict whether effects observed in the field and lab could lead to a shift back past the tipping point. This is a rare opportunity to study how oyster ecosystems can shift back from altered to healthy states. However, a rapid response is essential before seasonal changes in the weather and bay obscure hurricane impacts. This research has several broader impacts. First, it will expand the ecological theory of tipping points. Second, it can support the management of the Apalachicola Bay oyster fishery, such as insight into the likely success of restoration efforts. The team coordinates with the Apalachicola National Estuarine Research Reserve to this end. Finally, research outputs are incorporated into ongoing public education and training efforts.Ecosystems can rapidly shift from their original, high-value state to a new, degraded one. Such shifts have been observed in many ecosystems, but it is sometimes difficult to identify the mechanisms that mediate the shift beyond a "tipping point" and - to a greater extent - those that could mediate a shift back to the original state. Improving our understanding and predictive capability of tipping points depends on identifying the mechanisms that underlie bi-directional system shifts. In 2012, the oyster reefs of Apalachicola Bay, FL abruptly shifted into an oyster-less state when prolonged drought and low river flow allowed marine oyster predators to flourish. Despite subsequent years of normal rainfall and flow, there has not been a return shift, suggesting this ecosystem may have entered an alternate stable state. The hypothesis of this work is that in 2018 Hurricane Michael provided a sufficient disturbance to shift the system back into the attracting basin for its original state (prior observations support this prediction). This project couples field observations and lab experiments with population modeling to test whether and how Hurricane Michael initiated a reversal shift. A rapid response is essential before seasonal variability in this ecosystem obscures hurricane effects. The proposal's intellectual merit is based on its ability to address a central goal in ecology: identifying and predicting ecosystem tipping points. Combining empirical observations and models is a promising approach to advance this goal, but has not been widely applied in the field, mainly because researchers are not in place at the time of a shift. Hurricane Michael provides a unique opportunity to address this knowledge gap.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.

生态系统可以表现出“引诱点”，从而使环境干扰将生态系统推向了变化的状态，即使环境正常化，它也不会从中恢复。这可能是在2012年在佛罗里达西北部的有价值的牡蛎礁发生的，当时干旱和低河流使牡蛎的掠食者蓬勃发展，几乎消耗了所有牡蛎。尽管随后降雨正常和河流流量，但牡蛎尚未恢复，这表明生态系统可能已经越过临界点。但是，迈克尔飓风（Michael（2018））的干扰时间和幅度可能使生态系统恢复到其原始健康状态。在该项目中，调查人员进行了现场观察，以评估捕食者和牡蛎如何应对飓风迈克尔并进行实验室实验，以测试掠食者和牡蛎如何应对飓风降雨状况。此外，他们使用数学模型来预测在现场和实验室中观察到的效果是否会导致回流点的转移。这是研究牡蛎生态系统如何从改变变为健康状态的难得的机会。但是，在天气变化和海湾掩盖飓风影响之前，快速反应是必不可少的。这项研究具有更广泛的影响。首先，它将扩大临界点的生态理论。其次，它可以支持Apalachicola湾牡蛎渔业的管理，例如深入了解恢复工作的成功。该团队与阿帕拉奇科拉国家河口研究保护区协调了这一目标。最后，将研究成果纳入正在进行的公共教育和培训工作中。生态系统可以迅速从其原始的高价值状态转变为新的，退化的状态。在许多生态系统中都观察到了这种转变，但是有时很难确定介导超越“临界点”的转变的机制，并且在更大程度上 - 那些可以介导向原始状态的转移的机制。提高临界点的理解和预测能力取决于确定双向系统转移的机制。 2012年，佛罗里达州阿帕拉奇科拉湾（Apalachicola Bay）的牡蛎礁突然转移到了一个无牡蛎状态，当时长期干旱和低河流使海洋牡蛎捕食者蓬勃发展。尽管降雨正常和流动的正常降雨，但尚未发生返回，这表明该生态系统可能已经进入了另一种稳定状态。这项工作的假设是，迈克尔飓风在2018年提供了足够的干扰，将系统转移到吸引盆地的原始状态（先前的观察结果支持这一预测）。该项目将现场观测和实验室实验与人口建模进行，以测试迈克尔飓风是否以及如何开始逆转转变。在该生态系统中季节性变异性之前，快速反应是必不可少的，掩盖了飓风的影响。该提议的知识优点是基于其解决生态中心目标的能力：识别和预测生态系统介入点。结合经验观察和模型是一种有前途的方法，可以推进这一目标，但并未在现场广泛应用，这主要是因为研究人员在转变时没有建立。迈克尔飓风提供了一个独特的机会来解决这一知识差距。该奖项反映了NSF的法定使命，并被认为是值得通过基金会的知识分子优点和更广泛影响的评论标准来评估值得支持的。