Carvajal-Endara Sofía, Hendry Andrew P, Emery Nancy C, Davies T Jonathan
Department of Biology, McGill University, 1205 Ave Docteur Penfield, Montreal, QC, H3A 1B1, Canada.
Redpath Museum, McGill University, 859 Sherbrooke Street West, Montreal, QC, H3A 2K6, Canada.
Ecol Lett. 2017 Apr;20(4):495-504. doi: 10.1111/ele.12753. Epub 2017 Mar 10.
Remote locations, such as oceanic islands, typically harbour relatively few species, some of which go on to generate endemic radiations. Species colonising these locations tend to be a non-random subset from source communities, which is thought to reflect dispersal limitation. However, non-random colonisation could also result from habitat filtering, whereby only a few continental species can become established. We evaluate the imprints of these processes on the Galápagos flora by analysing a comprehensive regional phylogeny for ~ 39 000 species alongside information on dispersal strategies and climatic suitability. We found that habitat filtering was more important than dispersal limitation in determining species composition. This finding may help explain why adaptive radiation is common on oceanic archipelagoes - because colonising species can be relatively poor dispersers with specific niche requirements. We suggest that the standard assumption that plant communities in remote locations are primarily shaped by dispersal limitation deserves reconsideration.
偏远地区，如海洋岛屿，通常物种相对较少，其中一些物种进而产生了地方特有辐射。殖民这些地区的物种往往是源群落中的一个非随机子集，这被认为反映了扩散限制。然而，非随机殖民也可能是由生境过滤导致的，即只有少数大陆物种能够立足。我们通过分析约39000个物种的综合区域系统发育以及扩散策略和气候适宜性信息，评估这些过程对加拉帕戈斯群岛植物群的影响。我们发现，在决定物种组成方面，生境过滤比扩散限制更为重要。这一发现可能有助于解释为什么适应性辐射在海洋群岛上很常见——因为殖民物种可能是扩散能力相对较差但有特定生态位要求的物种。我们认为，偏远地区植物群落主要由扩散限制塑造这一标准假设值得重新审视。
