MCR LTER: Coral Reef: Biodiversity has a positive but saturating effect on imperiled coral reefs; data for Clements and Hay 2021, Science Advances

Species loss threatens ecosystems worldwide, but the ecological processes and thresholds that underpin positive biodiversity effects among critically important foundation species, such as corals on tropical reefs, remain inadequately understood. In field experiments, we manipulated coral species richness and intraspecific density to test whether, and how, biodiversity affects coral productivity and survival. Corals performed better in mixed species assemblages. Improved performance was unexplained by competition theory alone, suggesting that positive effects exceeded agonistic interactions during our experiments. Peak coral performance occurred at intermediate species richness and declined thereafter. Positive effects of coral diversity suggest that species’ losses on degraded reefs make recovery more difficult and further decline more likely. Harnessing these positive interactions may improve ecosystem conservation and restoration in a changing ocean. This material is based upon work supported by the U.S. National Science Foundation under Grant No. OCE 16-37396 (and earlier awards) as well as a generous gift from the Gordon and Betty Moore Foundation. Research was completed under permits issued by the French Polynesian Government (Délégation à la Recherche) and the Haut-commissariat de la République en Polynésie Francaise (DTRT) (Protocole d'Accueil 2005-2022). This work represents a contribution of the Moorea Coral Reef (MCR) LTER Site. Datasets used in this study are available online from the BCO-DMO data system. Data for this paper can be found at (https://www.bco-dmo.org/project/837802).

全球范围内的物种丧失正威胁着各类生态系统，但针对热带珊瑚礁珊瑚这类至关重要的建群种（foundation species），支撑其所在群落生物多样性正向效应的生态过程与阈值，目前仍未得到充分认知。本研究通过野外操控实验，调控珊瑚物种丰富度与种内密度，以验证生物多样性是否以及如何影响珊瑚的生产力与存活率。结果显示，多物种集合群落中的珊瑚生长表现更佳。这一生长表现提升无法仅通过竞争理论阐释，表明本实验中生物多样性的正向效应超过了物种间的拮抗交互作用。珊瑚的生长表现峰值出现在中等物种丰富度水平，之后随物种丰富度进一步提升而下降。珊瑚多样性的正向效应表明，退化珊瑚礁上的物种丧失会加剧生态系统恢复难度，并进一步提升生态系统持续衰退的可能性。利用这类正向物种交互作用，或可助力全球变化背景下海洋生态系统的保护与修复工作。

本研究成果基于美国国家科学基金会（U.S. National Science Foundation）编号为OCE 16-37396（及此前资助项目）的拨款，以及戈登与贝蒂·摩尔基金会（Gordon and Betty Moore Foundation）的慷慨捐赠完成。本研究的开展已获得法属波利尼西亚政府（Délégation à la Recherche）以及法属波利尼西亚法国共和国高级专员公署（Haut-commissariat de la République en Polynésie Francaise, DTRT）签发的许可（2005-2022年接待议定书，Protocole d'Accueil 2005-2022）。本研究系莫雷阿珊瑚礁（Moorea Coral Reef, MCR）长期生态研究（Long-Term Ecological Research, LTER）站点的研究产出之一。

本研究使用的数据集可通过生物与化学海洋学数据管理办公室（Biological and Chemical Oceanography Data Management Office, BCO-DMO）数据系统在线获取。本文相关数据可访问以下链接获取：https://www.bco-dmo.org/project/837802。