UMR 9220 ENTROPIE, Université de La Réunion, Faculté des Sciences et Technologies & Laboratoire d'Excellence CORAIL, La Réunion, France.
UMR 249 PIMIT, Université de La Réunion, INSERM, CNRS, IRD, Plateforme Technologique CYROI, La Réunion, France.
PLoS One. 2019 Mar 22;14(3):e0214163. doi: 10.1371/journal.pone.0214163. eCollection 2019.
Coral recruitment refers to the processes allowing maintenance and renewal of coral communities. Recruitment success is therefore indispensable for coral reef recovery after disturbances. Recruitment processes are governed by a variety of factors occurring at all spatial and temporal scales, from centimetres to hundreds of kilometres. In the present context of rising disturbances, it is thus of major importance to better understand the relative importance of different scales in this variation, and when possible, the factors associated with these scales. Multiscale spatio-temporal variability of scleractinian coral recruitment was investigated at two of the Mascarene Islands: Reunion and Rodrigues. Recruitment rates and taxonomic composition were examined during three consecutive six-month periods from regional to micro-local scales (i.e. from hundreds of kilometres to few centimetres) and between two protection levels (no-take zones and general protection zones). Very low recruitment rates were observed. Rodrigues displayed lower recruitment rates than Reunion. Recruit assemblage was dominated by Pocilloporidae (77.9%), followed by Acroporidae (9.9%) and Poritidae (5.2%). No protection effect was identified on coral recruitment, despite differences in recruitment rates among sites within islands. Recruits were patchily distributed within sites but no aggregative effect was detected, i.e. the preferentially colonised tiles were not spatially grouped. Recruits settled mainly on the sides of the tiles, especially at Rodrigues, which could be attributed to the high concentration of suspended matter. The variability of recruitment patterns at various spatial scales emphasises the importance of micro- to macro-local variations of the environment in the dynamics and maintenance of coral populations. High temporal variability was also detected, between seasons and years, which may be related to the early 2016 bleaching event at Rodrigues. The low recruitment rates and the absence of protection effect raise questions about the potential for recovery from disturbances of coral reefs in the Mascarene Islands.
珊瑚补充繁殖是指允许珊瑚群落维持和更新的过程。因此，在受到干扰后，珊瑚礁的恢复离不开补充繁殖的成功。补充繁殖过程受各种因素的控制，这些因素发生在从厘米到数百公里的所有时空尺度上。在当前干扰不断增加的情况下，更好地了解不同尺度在这种变化中的相对重要性，以及可能与这些尺度相关的因素，是非常重要的。在马斯克林群岛的两个岛屿——留尼汪岛和罗德里格斯岛，研究了硬珊瑚补充繁殖的多尺度时空变异性。在从区域到微局部尺度（即从数百公里到几厘米）以及在两个保护水平（禁捕区和一般保护区）之间的三个连续六个月期间，检查了补充繁殖率和分类组成。观察到非常低的补充繁殖率。罗德里格斯岛的补充繁殖率低于留尼汪岛。补充繁殖的集合主要由石珊瑚科（77.9%）主导，其次是鹿角珊瑚科（9.9%）和滨珊瑚科（5.2%）。尽管岛屿内各地点的补充繁殖率存在差异，但没有发现保护对珊瑚补充繁殖的影响。补充繁殖的幼体在各地点呈斑块状分布，但没有聚集效应，即优先定植的瓷砖没有在空间上聚集。补充繁殖的幼体主要在瓷砖的侧面定居，特别是在罗德里格斯岛，这可能归因于高浓度的悬浮物质。在各种空间尺度上，补充繁殖模式的可变性强调了环境的微观到宏观局部变化在珊瑚种群的动态和维持中的重要性。还检测到了季节和年份之间的高时间可变性，这可能与罗德里格斯岛 2016 年早期的白化事件有关。低补充繁殖率和缺乏保护效应引起了对马斯克林群岛珊瑚礁从干扰中恢复的潜力的质疑。
