ABSTRACT: Coral reefs across the globe are facing threats from a variety of anthropogenic disturbances. Consequently, the proportional representation of live scleractinian corals in the benthic community has declined substantially in many regions. In contrast, parts of the reef ecosystem around Mo’orea (French Polynesia) have displayed remarkable rebound potential. Nevertheless, detailed studies of when, where, and to what extent reefs have been disturbed and subsequently recovered in the different reef habitats are lacking. Using long-term monitoring data (2004-2018), we reveal that the spatiotemporal dynamics of benthic communities differ markedly between the contiguous inner (fringing and barrier) and outer (fore) reefs. Coral communities on inner reefs vary spatially but were remarkably stable over 15 yr, exhibiting consistent levels of coral and algal cover, with no evidence for disturbance-driven regimes or community transitions. In contrast, the outer reefs showed marked declines in coral cover following consecutive acute disturbances, but coral recovered rapidly thereafter. Nevertheless, community composition changed significantly, with Pocillopora replacing Acropora as the dominant genus at several sites, indicating a more subtle but potentially critical transition into an alternative state defined by the prevalence of a single, fast-growing genus. Inner reef stability and outer reef recovery provide evidence that the effects of environmental disturbances and chronic anthropogenic stressors can manifest in fundamentally different ways, depending on prevailing conditions. Our results suggest important ecological and physical links between inner and outer reef systems that influence the observed dynamics, emphasizing that reef ecosystem management and conservation strategies need to consider all habitats.

中文翻译：

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对底栖群落的长期监测揭示了珊瑚礁干扰和恢复动态的空间决定因素

摘要：全球珊瑚礁正面临着各种人为干扰的威胁。因此，在许多地区，底栖群落中活石珊瑚的比例代表已大幅下降。相比之下，Mo'orea（法属波利尼西亚）周围的部分珊瑚礁生态系统显示出显着的反弹潜力。然而，缺乏对不同珊瑚礁栖息地中珊瑚礁何时、何地以及在何种程度上受到干扰并随后恢复的详细研究。使用长期监测数据（2004-2018），我们揭示了连续的内（边缘和屏障）和外（前）珊瑚礁之间底栖群落的时空动态显着不同。内礁上的珊瑚群落在空间上有所不同，但在 15 年中非常稳定，表现出一致的珊瑚和藻类覆盖水平，没有证据表明干扰驱动的制度或社区转变。相比之下，外礁在连续急性干扰后珊瑚覆盖率显着下降，但此后珊瑚迅速恢复。然而，社区组成发生了显着变化，Pocillopora取代Acropora作为几个地点的优势属，表明更微妙但潜在的关键转变为由单一、快速增长的属的流行定义的替代状态。内礁稳定性和外礁恢复提供了证据，表明环境干扰和慢性人为压力源的影响可以以根本不同的方式表现出来，具体取决于当时的条件。我们的结果表明内部和外部珊瑚礁系统之间的重要生态和物理联系会影响观察到的动态，强调珊瑚礁生态系统管理和保护策略需要考虑所有栖息地。