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，导致珊瑚礁覆盖率下降，但法属波利尼西亚莫雷亚的珊瑚礁是一个引人注目的例外。然而，目前尚不清楚是什么使莫雷亚的珊瑚群落成为全球珊瑚覆盖率下降趋势的例外，以及是什么导致了该岛周围恢复模式的空间差异。最近一波在外礁上的复苏是由花椰菜珊瑚属(Pocillopora)的珊瑚主导的。虽然这种珊瑚的群体看起来彼此相似，但它们实际上代表了多个在基因上存在分歧但明显难以区分的“隐藏”物种。这种形态上的相似性使得很难识别该领域的物种，这往往迫使研究人员将这些珊瑚集中到一个单独的组中，这阻碍了对珊瑚恢复的充分了解。这些隐藏物种之间的生态差异仍然知之甚少，但它们可能是使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”如何提供一种形式的“生态保险”，为岛屿周围的造礁珊瑚群落提供生态和进化选择，以缓冲珊瑚礁免受不可预测和不利环境条件的影响。如果多个神秘物种对干扰和压力表现出不同的反应，那么与所有物种都以相同的方式反应相比，它增加了群落在受到影响后恢复和重组的能力。通过对莫雷亚珊瑚礁的研究，该项目提供了独特的、重要的和可转移的知识，以更好地了解灾难性破坏后推动珊瑚群落恢复的基本机制，并将提供急需的信息，以更好地管理珊瑚礁，有利于珊瑚礁保持以珊瑚为主的状态。在该项目期间，佛罗里达州立大学(FSU)的一名博士生和一名博士后研究员得到了支持和指导，并为将参与该项目的技术人员提供了职业成长计划。研究人员正在与佛罗里达学校的科学教育工作者合作，引入海洋生物俱乐部，为FSU和加州州立大学北岭分校的参与者提供扩展机会，让高中生和老师参与到这个项目的核心研究主题中。这个项目将检验这样一个假设，即在法属波西里亚岛的外礁上，存在形态相似但基因不同的珊瑚谱系，推动由波西洛拉珊瑚主导的珊瑚群落迅速恢复。通过为波西洛拉群落在受到干扰后恢复和重组的能力创造一个多样化的组合，珊瑚谱系在应对干扰时隐藏的生态差异有望促进社区的复原力。一个经过充分研究的遗传标记将被用来区分不同谱系之间的珊瑚群体。实地项目与Moorea珊瑚礁-长期生态研究(MCR-LTER)地点同处一处，将确定小孔虫谱系在分布和丰度、年度补充的时空模式、共生体组成以及定居后生长和生存方面的差异。这些数据将被用来建立积分预测模型(IPMS)，以比较不同谱系之间的种群差异，它们对大小依赖的扰动的敏感性，以及它们在扰动后的种群增长能力。将综合实地项目和综合管理系统的结果，以估计响应多样性作为谱系差异的多变量离散程度，并评估根据MCR-LTER时间序列经验估计的地点间口袋孔虫覆盖率恢复率的差异程度。这个项目的学术价值在于发展了新的和可转移的理解：i)一个生态上重要的珊瑚属内的生态差异，ii)为什么莫雷亚的袋足类动物是全球珊瑚覆盖率下降趋势的例外，以及iii)隐藏响应多样性的潜力，作为决定珊瑚群落重建和重组后续干扰的能力的基本机制。这一奖项反映了NSF的法定使命，并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。

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.