RAPID: Understanding Thresholds and regime shifts in marine ecosystems: effects of the 2014-2015 El Nino in the Galapagos rocky subtidal

RAPID：了解海洋生态系统的阈值和状态转变：2014-2015 年厄尔尼诺现象对加拉帕戈斯岩石潮下带的影响

• 批准号: 1450214
• 负责人: Jon Witman
• 金额: $ 15.5万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1450214&HistoricalAwards=false
• 关键词: RAPID; Understanding; Thresholds; regime; shifts

The question addressed in this project is: Does the 2014-2015 El Niño cause a regime shift in Galapagos subtidal ecosystems? And if so, what thresholds are crossed to drive the change from rocky subtidal communities with abundant corals to a barnacle dominated regime? Regime shifts are non-linear "ecological surprises" in the sense that the endpoint is not predictable as a linear outcome of a driver variable. The working hypothesis for this project is that the forthcoming 2014-2015 El Niño will create non-linear effects that are negative for corals which bleach during extreme temperature variability of the El Niño Southern Oscillation (ENSO), but are positive for the benthic (bottom dwelling) food chain dependent on barnacles for food. The specific work in the Galapagos will contribute to the general understanding of non-linear effects of climate stress in marine ecosystems, which has been highlighted as a critical information gap needed to understand the effects of climate change on ecosystems. The study will also inform best practices for the conservation of corals, which are threatened worldwide by multiple stressors and cumulative direct, and indirect impacts. Broader educational impacts of the one-year project will transpire at all levels from high school students to graduate students. For example, the research program will provide valuable mentoring of a Brown University PhD student in subtidal field ecology and climate science. Undergraduate students will benefit from enhanced lectures on ecological impacts of climate oscillations in a large Ecology course at Brown and from training in the lab. The research team is committed to expanding outreach beyond these venues by fostering ocean and climate change literacy in presentations about the research results to local high schools. Perturbations such as El Niños can drive ecosystems to a tipping point as thresholds are exceeded and a sudden transition to a different state (regime) occurs. Since the frequency of extreme El Niños is projected to increase with climate change, there is a pressing need to develop a more comprehensive understanding of how ENSOs affect marine communities in the context of climate change. Currently, the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center predicts a 70-80 % chance of an El Niño occurring during the northern hemisphere summer-winter of 2014-2015. This project leverages an existing quantitative baseline on benthic community structure in the Galapagos subtidal to address 12 predictions about community-ecosystem level impacts of the oncoming 2014-2015 El Niño. The research employs an observational-experimental approach to test the predictions and to discern if additional bleaching stress to corals and further increases in barnacles associated with this ENSO ultimately leads to an ecosystem state (regime) characterized by declining coral populations and increasing barnacles and their predators.

该项目涉及的问题是：2014-2015年厄尔尼诺现象是否导致加拉帕戈斯潮下生态系统的制度转变？如果是这样的话，是什么门槛推动了从珊瑚丰富的岩石潮下群落到藤壶主宰的制度的转变？制度变迁是一种非线性的“生态意外”，因为终点作为驱动变量的线性结果是不可预测的。该项目的工作假设是，即将到来的2014-2015年厄尔尼诺现象将产生非线性影响，对在厄尔尼诺南方涛动(ENSO)极端温度变化期间漂白的珊瑚不利，但对依赖藤壶作为食物的底栖(底层)食物链是积极的。加拉帕戈斯群岛的具体工作将有助于全面了解气候压力对海洋生态系统的非线性影响，这已被强调为了解气候变化对生态系统的影响所需的关键信息缺口。这项研究还将介绍保护珊瑚的最佳做法，珊瑚在世界各地受到多重压力以及累积的直接和间接影响的威胁。这一为期一年的项目将在从高中生到研究生的所有级别产生更广泛的教育影响。例如，该研究计划将为布朗大学的一名博士生提供潮滩生态学和气候科学方面的宝贵指导。本科生将受益于布朗大学大型生态学课程中关于气候振荡的生态影响的强化讲座，以及实验室的培训。研究小组致力于通过在向当地高中介绍研究成果时培养海洋和气候变化素养，将范围扩大到这些场所以外。厄尔尼诺现象等扰动会使生态系统达到临界点，因为超过了阈值，就会突然过渡到不同的状态(状态)。由于极端厄尔尼诺现象的频率预计将随着气候变化而增加，因此迫切需要更全面地了解ENSO如何在气候变化的背景下影响海洋社区。目前，美国国家海洋和大气管理局(NOAA)气候预测中心预测，2014-2015年北半球夏冬期间发生厄尔尼诺现象的可能性为70%-80%。该项目利用加拉帕戈斯潮下带现有底栖群落结构的量化基线，对即将到来的2014-2015年厄尔尼诺现象对群落生态系统水平的影响进行12项预测。该研究采用观测-实验方法来验证预测，并查明与ENSO相关的对珊瑚的额外漂白压力和藤壶的进一步增加最终是否会导致以珊瑚数量下降、藤壶及其捕食者增加为特征的生态系统状态(状态)。