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

• 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

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.

生态系统可能会出现“临界点”，环境扰动会将生态系统推入改变的状态，即使环境恢复正常，生态系统也无法恢复。 2012年，这种情况可能发生在佛罗里达州西北部珍贵的牡蛎礁上，当时干旱和河水流量低，导致牡蛎捕食者大量繁殖，几乎吃掉了所有牡蛎。尽管随后几年降雨量和河流流量正常，但牡蛎尚未恢复，这表明生态系统可能已经跨越了临界点。然而，迈克尔飓风（2018 年）造成的干扰的时间和强度可能已使生态系统恢复到原来的健康状态。 在该项目中，研究人员进行实地观察，以了解捕食者和牡蛎如何应对迈克尔飓风，并进行实验室实验，以测试捕食者和牡蛎如何应对飓风降雨条件。此外，他们使用数学模型来预测在现场和实验室观察到的影响是否可能导致回到临界点。这是研究牡蛎生态系统如何从改变状态恢复到健康状态的难得机会。然而，在天气季节性变化和海湾飓风影响变得模糊之前，快速反应至关重要。这项研究有几个更广泛的影响。首先，它将扩展临界点的生态理论。其次，它可以支持阿巴拉契科拉湾牡蛎渔业的管理，例如了解恢复工作可能成功的情况。为此，该团队与阿巴拉契科拉国家河口研究保护区进行协调。最后，研究成果被纳入持续的公共教育和培训工作中。生态系统可以迅速从原来的高价值状态转变为新的退化状态。在许多生态系统中都观察到了这种转变，但有时很难确定介导超越“临界点”的转变的机制，以及在更大程度上介导返回原始状态的机制。提高我们对临界点的理解和预测能力取决于识别双向系统转变背后的机制。 2012年，由于长期干旱和河水流量低，导致海洋牡蛎捕食者大量繁殖，佛罗里达州阿巴拉契科拉湾的牡蛎礁突然进入无牡蛎状态。尽管随后几年降雨量和流量正常，但并未出现回归变化，这表明该生态系统可能已进入另一种稳定状态。这项工作的假设是，2018 年迈克尔飓风提供了足够的扰动，使系统回到原始状态的吸引盆地（之前的观察结果支持这一预测）。该项目将现场观察和实验室实验与人口模型结合起来，以测试飓风迈克尔是否以及如何引发逆转。在该生态系统的季节性变化掩盖飓风影响之前，快速反应至关重要。该提案的智力价值基于其解决生态学核心目标的能力：识别和预测生态系统临界点。将经验观察和模型相结合是推进这一目标的一种有前途的方法，但尚未在该领域得到广泛应用，主要是因为研究人员在转变时还没有到位。飓风迈克尔为解决这一知识差距提供了一个独特的机会。该奖项反映了 NSF 的法定使命，并且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。

项目成果

Diminishing returns in habitat restoration by adding biogenic materials: a test using estuarine oysters and recycled oyster shell

通过添加生物材料减少栖息地恢复的回报：使用河口牡蛎和回收牡蛎壳进行的测试

• DOI: 10.1111/rec.13227
• 发表时间: 2020-09
• 期刊: Restoration Ecology
• 影响因子: 3.2
• 作者: Kimbro, David L.;Stallings, Christopher D.;White, James W.
• 通讯作者: White, James W.