Université de La Réunion, UMR 9220 ENTROPIE, Faculté des Sciences et Technologies, 97744, Saint Denis Cedex 9, La Réunion, France.
Laboratoire d'Excellence "CORAIL", Paris, France.
Sci Rep. 2020 Nov 30;10(1):20821. doi: 10.1038/s41598-020-77665-z.
Understanding colonization of new habitats and ecological successions is key to ecosystem conservation. However, studies on primary successions are scarce for reef-building corals, due to the rarity of newly formed substratum and the long-term monitoring efforts required for their long life cycle and slow growth rate. We analysed data describing the diversity, structure and demography of coral assemblages on lava flows of different ages and coral reefs at Reunion Island, to evaluate the strength and mechanisms of succession, and its agreement to the theoretical models. No significant differences were observed between the two habitats for most structure and demographic descriptors. In contrast, species richness and composition differentiated coral reefs from lava flows, but were not related to the age of the lava flow. We observed a strong dominance of Pocillopora colonies, which underline the opportunistic nature of this taxa, with life-history traits advantageous to dominance on primary and secondary successional stages. Although some results argue in favor of the tolerance model of succession, the sequences of primary successions as theorized in other ecosystems were difficult to observe, which is likely due to the high frequency and intensity of disturbances at Reunion, that likely distort or set back the expected successional sequences.
理解新栖息地的定居和生态演替对于生态系统保护至关重要。然而，由于新形成的基质稀少，以及珊瑚礁寿命长、生长缓慢，需要长期监测，因此针对造礁石珊瑚的原生演替研究很少。我们分析了描述留尼汪岛熔岩流和珊瑚礁不同年龄珊瑚群落在多样性、结构和种群动态的数据，以评估演替的强度和机制及其与理论模型的一致性。在大多数结构和人口统计学描述符方面，两个栖息地之间没有观察到显著差异。相比之下，珊瑚礁和熔岩流之间的物种丰富度和组成存在差异，但与熔岩流的年龄无关。我们观察到了明显的石珊瑚属优势，这突显了该类群的机会主义性质，其生活史特征有利于在原生和次生演替阶段占主导地位。尽管有些结果支持演替的耐受模型，但在其他生态系统中理论化的原生演替序列很难观察到，这可能是由于留尼汪岛频繁而强烈的干扰，这些干扰可能会扭曲或阻碍预期的演替序列。
