Briggs Amy A, Brown Anya L, Osenberg Craig W
Odum School of Ecology, University of Georgia, Athens, GA, USA.
Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
R Soc Open Sci. 2021 Sep 15;8(9):210035. doi: 10.1098/rsos.210035. eCollection 2021 Sep.
Microbes influence ecological processes, including the dynamics and health of macro-organisms and their interactions with other species. In coral reefs, microbes mediate negative effects of algae on corals when corals are in contact with algae. However, it is unknown whether these effects extend to larger spatial scales, such as at sites with high algal densities. We investigated how local algal contact and site-level macroalgal cover influenced coral microbial communities in a field study at two islands in French Polynesia, Mo'orea and Mangareva. At 5 sites at each island, we sampled prokaryotic microbial communities (microbiomes) associated with corals, macroalgae, turf algae and water, with coral samples taken from individuals that were isolated from or in contact with turf or macroalgae. Algal contact and macroalgal cover had antagonistic effects on coral microbiome alpha and beta diversity. Additionally, coral microbiomes shifted and became more similar to macroalgal microbiomes at sites with high macroalgal cover and with algal contact, although the microbial taxa that changed varied by island. Our results indicate that coral microbiomes can be affected by algae outside of the coral's immediate vicinity, and local- and site-level effects of algae can obscure each other's effects when both scales are not considered.
微生物影响生态过程，包括大型生物的动态变化与健康状况以及它们与其他物种的相互作用。在珊瑚礁中，当珊瑚与藻类接触时，微生物会介导藻类对珊瑚的负面影响。然而，这些影响是否会扩展到更大的空间尺度，比如在藻类密度高的区域，目前尚不清楚。我们在法属波利尼西亚的莫雷阿岛和芒阿雷瓦岛的实地研究中，调查了局部藻类接触和区域尺度的大型藻类覆盖度如何影响珊瑚微生物群落。在每个岛屿的5个地点，我们对与珊瑚、大型藻类、丝状藻类和水相关的原核微生物群落（微生物组）进行了采样，珊瑚样本取自与丝状藻类或大型藻类隔离或接触的个体。藻类接触和大型藻类覆盖度对珊瑚微生物组的α和β多样性具有拮抗作用。此外，在大型藻类覆盖度高且存在藻类接触的地点，珊瑚微生物组发生了变化，并且变得与大型藻类微生物组更加相似，尽管不同岛屿上发生变化的微生物类群有所不同。我们的结果表明，珊瑚微生物组可能会受到珊瑚紧邻区域之外的藻类的影响，并且当不考虑两个尺度时，藻类的局部和区域尺度效应可能会相互掩盖。
