Positive Effects of Coral Biodiversity on Coral Performance: Patterns, Processes, and Dynamics

珊瑚礁极其多样化，提供关键的生态系统服务，并正在以惊人的速度崩溃，近几十年来，加勒比地区的珊瑚损失了80%，太平洋地区的珊瑚损失了50%。以往的研究强调负面的相互作用（竞争，捕食）结构珊瑚礁系统，但积极的相互作用，在这样的物种丰富的系统可能是同样重要的，在维持生态系统功能。如果像珊瑚这样的基础物种依赖于积极的相互作用，那么它们的适应性可能会随着周围物种的丧失而下降，从而造成生物多样性的崩溃，其中一种珊瑚的丧失会导致其他物种的丧失。该项目进行实地实验，以了解珊瑚生物多样性在促进珊瑚生长、生存、复原力和保留这些基础物种方面的作用，以及它们在热带浅海提供的关键生态系统服务。该项目致力于：1）教育和激励有影响力的商业和民间领袖，在这些系统失去生态功能和价值之前保护和恢复沿海海洋系统。这将涉及北格鲁吉亚/亚特兰大（美国东南部的主要经济引擎）内有影响力的扶轮社作为最初的焦点。2)利用格鲁吉亚理工学院的研究新闻和研究所通信办公室以及与科学作家的良好联系，制作关于这些研究中出现的重要海洋生态学发现的流行新闻稿。(3)组织了一次由国际知名科学家参加的公共讲习班，重点是维护海洋生物多样性，以此作为维持生态系统服务和沿海文化与经济的战略。调查人员以前组织的类似活动吸引了大约200人参加，并向格鲁吉亚的许多高中和无法参加的欠发达国家的外国调查人员进行了网上直播。演讲者还对当地高中班级进行了面对面的视频采访。由于这一成功，这种模式将被重复。4)与法属波利尼西亚教育工作者和文化领袖协会合作，制作关于我们工作和珊瑚礁养护的电子格式演示文稿，适合波利尼西亚文化中的教师和领导人使用。 生态学家擅长证明物种对之间直接（通常是负面）相互作用的重要性。然而，当这些相互作用发生在该领域数千个其他物种之间的复杂背景下时，许多鲜为人知的间接相互作用的总和可以抵消，甚至逆转，更好地了解直接相互作用，产生扩散互惠而不是竞争结果。在概念验证的初步实验中，珊瑚的生长和存活率在珊瑚复合养殖中比单一养殖更大，特别是在社区发展的早期阶段。产生这种结果的过程尚不清楚，但了解这些是至关重要的，因为珊瑚礁的多样性和功能下降，人类需要预测和适应不断变化的环境。这种跨学科的调查融合了实验场生态学，化学生态学和微生物生态学的专业知识，以调查生物多样性在珊瑚礁生态系统中的功能作用。实验使用一种新的珊瑚移植方法和现场操作来评估：1）更大的珊瑚物种多样性是否增强了珊瑚群落的性能，以及个体珊瑚的生长和存活，2）更大的基因型多样性是否增强了物种内的珊瑚性能，3）更大的海藻竞争者多样性是否进一步抑制了珊瑚并增强了海藻性能，以及4）驱动上述模式的过程，包括疾病、种内与种间竞争、捕食者、互利主义者以及对资源的不同获取或使用的作用。该研究调查了生物多样性和生态系统功能之间的关系，从物种到基因型的珊瑚分类多样性的各个方面，并创建了一系列实验，阐明生态系统动力学的一般原则。填补这些知识空白推进了我们对生物多样性如何在多个尺度上影响生态系统功能的基本理解，并深入了解了促进珊瑚在这些物种丰富的生态系统中共存的过程。研究结果将对珊瑚管理和恢复产生实际影响，并可能改善对珊瑚礁在气候变化中的恢复力和恢复的预测。该奖项反映了NSF的法定使命，并被认为值得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来支持。

Coral reefs are extremely diverse, supply critical ecosystem services, and are collapsing at an alarming rate, with 80% coral loss in the Caribbean and 50% in the Pacific in recent decades. Previous studies emphasized negative interactions (competition, predation) as structuring reef systems, but positive interactions in such species-rich systems could be of equal importance in maintaining ecosystem function. If foundation species like corals depend on positive interactions, then their fitness may decline with the loss of surrounding species, creating a biodiversity meltdown where loss of one coral causes losses of others. This project conducts manipulative field experiments to understand the role of coral biodiversity in facilitating coral growth, survival, resilience, and retention of these foundation species and the critical ecosystem services they provide in shallow tropical seas. This project is committed to: 1) Educating and exciting influential business and civic leaders about conservation and restoration of coastal marine systems before these systems lose ecological function and value. This will involve influential Rotary clubs within North Georgia/Atlanta (the major economic engine of the southeastern US) as an initial focus. 2) Using the Research News and Institute Communications Office at Georgia Tech and well-developed contacts with science writers to produce popular press pieces on important ocean ecology discoveries emerging from these studies. (3) Organizing a public workshop of internationally prominent scientists focused on Maintaining Marine Biodiversity as a Strategy to Sustain Ecosystem Services and Coastal Cultures and Economies. A previous effort like this, organized by the investigators, attracted about 200 attendees and was webcast to numerous high schools in Georgia and to foreign investigators in less developed countries that could not attend. Speakers also conducted in-person video interviews with local high school classes. Due to that success, this model will be repeated. 4) Working with an association of educators and cultural leaders in French Polynesia to produce electronic format presentations on our work and on reef conservation that are appropriate for use by both teachers and leaders within Polynesian culture. Ecologists have excelled at demonstrating the importance of direct (often negative) interactions among species pairs. However, when these interactions occur in a complex context among thousands of other species in the field, the sum of the many, poorly-known, indirect interactions can counterbalance, or even reverse, the better-known direct interactions, generating diffuse mutualisms instead of agonistic outcomes. In a proof-of-concept initial experiment, coral growth and survivorship were greater in coral polycultures than monocultures, especially during early stages of community development. Processes generating this outcome are unclear but understanding these is of critical importance as diversity and function of reefs decline and as humans need to predict and adapt to changing environments. This interdisciplinary investigation merges expertise in experimental field ecology, chemical ecology, and the ecology of microbiomes to investigate the functional role of biodiversity in coral reef ecosystems. Experiments use a novel coral transplantation method and field manipulations to assess: 1) whether greater coral species diversity enhances coral community performance, as well as growth and survivorship of individual corals, 2) whether greater genotypic diversity enhances coral performance within a species, 3) whether greater diversity of seaweed competitors further suppresses corals and enhances seaweed performance, and 4) the processes driving the patterns documented above, including the roles of disease, intraspecific versus interspecific competition, predators, mutualists, and differential access to, or use of, resources. The research investigates the relationship between biodiversity and ecosystem function across dimensions of coral taxonomic diversity, from species to genotypes, and creates a series of experiments elucidating general principles underlying ecosystem dynamics. Filling these knowledge gaps advances our fundamental understanding of how biodiversity influences ecosystem function at multiple scales and provides insight into the processes promoting coral coexistence in these species-rich ecosystems. Findings will have practical implications for coral management and restoration and may improve predictions regarding coral reef resilience and recovery in the face of changing climate.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.