School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia.
Nat Commun. 2023 Apr 17;14(1):2181. doi: 10.1038/s41467-023-37550-5.
Temperate reefs are at the forefront of warming-induced community alterations resulting from poleward range shifts. This tropicalisation is exemplified and amplified by tropical species' invasions of temperate herbivory functions. However, whether other temperate ecosystem functions are similarly invaded by tropical species, and by what drivers, remains unclear. We examine tropicalisation footprints in nine reef fish functional groups using trait-based analyses and biomass of 550 fish species across tropical to temperate gradients in Japan and Australia. We discover that functional niches in transitional communities are asynchronously invaded by tropical species, but with congruent invasion schedules for functional groups across the two hemispheres. These differences in functional group tropicalisation point to habitat availability as a key determinant of multi-species range shifts, as in the majority of functional groups tropical and temperate species share functional niche space in suitable habitat. Competition among species from different thermal guilds played little part in limiting tropicalisation, rather available functional space occupied by temperate species indicates that tropical species can invade. Characterising these drivers of reef tropicalisation is pivotal to understanding, predicting, and managing marine community transformation.
温带珊瑚礁处于因极向范围转移而导致的变暖引起的群落变化的前沿。这种热带化的例子是由热带物种入侵温带草食性功能来放大的。然而，其他温带生态系统功能是否也同样受到热带物种的入侵，以及受到哪些驱动因素的影响，目前尚不清楚。我们使用基于特征的分析和日本和澳大利亚从热带到温带梯度的 550 种鱼类的生物量，检查了 9 种珊瑚鱼功能组的热带化足迹。我们发现，过渡群落的功能生态位被热带物种异步入侵，但在两个半球的功能组中具有一致的入侵时间表。这些功能组热带化的差异表明，栖息地的可利用性是物种多区域转移的关键决定因素，因为在大多数功能组中，热带和温带物种在适宜的栖息地中共享功能生态位空间。来自不同热群的物种之间的竞争在限制热带化方面作用不大，而是温带物种占据的可用功能空间表明热带物种可以入侵。描述这些珊瑚礁热带化的驱动因素对于理解、预测和管理海洋群落的转变至关重要。
