Predator identity influences metacommunity assembly

1.Predation is among the most important biotic factors influencing natural communities, yet we have a rather rudimentary understanding of its role in modulating metacommunity assembly. 2.We experimentally examined the effects of two different predators (a generalist and a specialist) on metacommunity assembly, using protist microcosm metacommunities that varied in predator identity, dispersal among local communities, and the history of species colonization into local communities. 3.Generalist predation resulted in reduced α diversity and increased β diversity irrespective of dispersal, likely due to predation-induced stochastic extinction of different prey species in different local communities. Dispersal, however, induced source-sink dynamics in the presence of specialist predators, resulting in higher α diversity and marginally lower β diversity. 4.These results demonstrate the distinct effects of different predators on prey metacommunity assembly, emphasizing the need to explore t...1. 捕食作用是影响自然群落的核心生物因子之一，但当前我们对其在调控集合群落（metacommunity）组装过程中的作用仍仅有极为粗浅的认知。 2. 本研究以原生动物微宇宙集合群落（protist microcosm metacommunity）为实验模型，设置捕食者类型（广食性与专食性两类）、局域群落间扩散强度以及局域群落物种定殖历史三类可变因素，通过实验探究了两类不同捕食者对集合群落组装过程的影响。 3. 无论扩散水平如何，广食性捕食作用均会降低α多样性并提升β多样性，该现象大概率源于捕食作用诱导不同局域群落中的猎物物种发生随机灭绝。而在专食性捕食者存在的情境下，扩散会引发源-汇动态，最终导致更高的α多样性与略微更低的β多样性。 4. 本研究结果证实了不同捕食者对猎物种集合群落组装过程的差异化影响，凸显了深入探究捕食者在集合群落生态学中复杂作用的必要性……