Collaborative research: Coral community resilience: testing the role of hidden diversity in pocilloporid corals at Moorea

虽然世界上大多数珊瑚礁都受到多种干扰的威胁，导致珊瑚覆盖面积下降，但法属波利尼西亚莫奥利亚的珊瑚礁却是一个明显的例外。然而，目前尚不清楚是什么使Mo'orea的珊瑚群落成为全球珊瑚覆盖下降趋势的例外，以及是什么驱动了该岛周围恢复模式的空间变化。最近一波外礁的恢复主要是花椰菜珊瑚属的珊瑚。虽然这些珊瑚群看起来都很相似，但它们实际上代表了多个“隐藏”的物种，这些物种在基因上存在差异，但在表面上无法区分。形态上的相似性使得在野外很难识别物种，这常常迫使研究人员将这些珊瑚集中到一个群体中，这阻碍了对珊瑚恢复的全面了解。这些隐藏物种之间的生态差异仍然知之甚少，但它们可能是保持生态系统处于珊瑚主导状态的关键因素。该项目正在研究“隐藏的多样性”如何提供一种“生态保险”形式，为该岛周围的造礁珊瑚群落提供生态和进化选择，缓冲珊瑚礁免受不可预测和不利环境条件的影响。如果多个隐种对干扰和压力的响应表现出多样性，那么与所有物种的响应方式相同相比，它增加了群落在影响后恢复和重组的能力。通过对Mo'orea珊瑚礁的研究，该项目为更好地了解灾难性破坏后珊瑚群落恢复的基本机制提供了独特、重要和可转移的知识，并将为更好地管理珊瑚礁提供急需的信息，并有利于它们保持以珊瑚为主的状态。在项目期间，佛罗里达州立大学（FSU）的一名博士生和一名博士后研究员将得到支持和指导，并为将参与该项目的一名技术人员提供专业成长计划。研究人员正在与佛罗里达学校的科学教育工作者合作，引入海洋生物学俱乐部，为FSU和加州州立大学北岭分校的参与者提供拓展机会，让高中生和教师参与到该项目的核心研究主题中来。该项目将测试一种假设，即形态相似但基因不同的Pocillopora属珊瑚谱系的存在，推动了法属波利尼西亚Mo'orea外礁上以Pocillopora为主的珊瑚群落的快速恢复。通过创造一个多样化的组合，使poillopora群落在受到干扰后恢复和重组的能力，珊瑚谱系之间在对干扰的反应中隐藏的生态差异有望促进群落的恢复能力。一个经过充分研究的遗传标记将用于区分不同谱系的珊瑚群落。实地项目将与Moorea珊瑚礁长期生态研究（MCR-LTER）地点共同选址，以确定pocilloporid谱系在其分布和丰度、年度补充的时空模式、共生组成以及定居后的生长和生存方面的差异。这些数据将用于建立积分投影模型（IPMs），以比较不同谱系对大小相关扰动的敏感性差异，以及它们在扰动后的种群增长能力。将综合实地项目和ipm的结果，以估计响应多样性作为谱系不相似性的多变量分散，并评估其预测从MCR-LTER时间序列中经验估计的pocilloporid百分比覆盖率恢复率在不同地点之间变化的程度。这个项目的知识价值在于对以下问题有了新的、可转移的认识：1)生态上重要的珊瑚属内部的生态差异；2)为什么Mo'orea的pocilloporids是珊瑚覆盖减少的全球趋势的一个例外；3)隐藏响应多样性的潜力，作为决定珊瑚群落在干扰后重建和重组能力的基本机制。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

While most coral reefs in the world are threatened by multiple disturbances that are driving coral cover downward, the coral reefs at Mo'orea, French Polynesia, provide a striking exception. However, it is not yet clear what makes the coral communities of Mo'orea an exception to the trend of global decline in coral cover, and what drives spatial variation in recovery patterns around the island. The most recent wave of recovery on the outer reefs is dominated by corals in the genus Pocillopora (the cauliflower coral). While the colonies of this coral all look similar to one another, they actually represent multiple 'hidden' species that are genetically divergent but visibly indistinguishable. The morphological similarity makes it hard to identify species in the field, and this often forces researchers to pool these corals into a single group, which has impeded a full understanding of coral recovery. The ecological differences among these hidden species remain poorly understood, but they may be a crucial factor keeping the ecosystem in a coral-dominated state. This project is studying how 'hidden diversity' provides a form of 'ecological insurance' that provides reef-building coral communities around this island with ecological and evolutionary options that buffer reefs from unpredictable and unfavorable environmental conditions. If multiple cryptic species exhibit a diversity of responses to disturbance and stress, then it increases the ability of the community to recover and re-organize after impacts compared to that if all the species responded the same way. By studying the reefs at Mo'orea, this project provides unique, important, and transferable knowledge to better understand fundamental mechanism driving coral community recovery following catastrophic damage, and will provide much-needed information to better manage coral reefs and favor them remaining in a coral-dominated state. A PhD student and a postdoctoral researcher at Florida State University (FSU) are being supported and mentored during the project, and a program of professional growth is being provided for a technician who will work on the project. The investigators are working with science educators from Florida schools to introduce marine biology clubs that will provide outreach opportunities for FSU and California State University Northridge participants to engage high school students and teachers in the research themes at the core of this project.This project will test the hypothesis that the presence of morphologically similar yet genetically divergent lineages of corals in the genus Pocillopora drives rapid recovery of coral communities dominated by Pocillopora on the outer reefs of Mo'orea, French Polynesia. By creating a diverse portfolio in the capacity of the Pocillopora community to recover and reorganize after disturbance, hidden ecological differences among coral lineages in their response to disturbance is expected to promote community resilience. A well-studied genetic marker will be used to distinguish coral colonies among different lineages. Field-based projects, co-located with Moorea Coral Reef-Long-Term Ecological Research (MCR-LTER) sites, will determine how pocilloporid lineages differ in their distribution and abundance, spatial and temporal patterns of annual recruitment, symbiont composition, and post-settlement growth and survival. These data will be used to build Integral Projection Models (IPMs) to compare population differences among lineages in their sensitivity to size-dependent perturbations, and their capacity for population growth following disturbance. Results from the field projects and IPMs will be synthesized to estimate response diversity as the multivariate dispersion of lineage dissimilarity, and to assess the extent to which it predicts variation among sites in the recovery rate of pocilloporid percent cover, estimated empirically from the MCR-LTER time series. The intellectual merits of this project lie in developing new and transferable understanding of: i) the ecological differences within an ecologically important coral genus, ii) why pocilloporids at Mo'orea are an exception to the global trend of declining coral cover, and iii) the potential for hidden response diversity to act as a fundamental mechanism determining the capacity for coral communities to reestablish and reorganize following disturbances.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.