Community assembly in Lake Tanganyika cichlid fish: quantifying the contributions of both niche-based and neutral processes.
Community assembly in Lake Tanganyika cichlid fish: quantifying the contributions of both niche-based and neutral processes.
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DOI：
10.1002/ece3.2689
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发表时间：
2017-02
影响因子：
2.6
通讯作者：
Etienne RS
中科院分区：
文献类型：
--
作者：
Janzen T;Alzate A;Muschick M;Maan ME;van der Plas F;Etienne RS
慈鲷科的特点是一些最壮观的例子适应辐射。进化研究强调了营养适应和性选择在慈鲷物种形成中的重要性。然而，它是知之甚少的过程驱动的组成和多样性的本地慈鲷物种组合相对较短的生态时间尺度。在这里，我们调查的相对重要性，生态位为基础的和中性的过程，在确定的组成和多样性的慈鲷群落栖息在不同的环境条件下的沿岸的区坦噶尼喀湖，赞比亚。我们收集了慈鲷丰度，形态测量学和当地环境的数据。我们分析了平均性状值，社区组成和环境变化之间的关系，并使用最近开发的建模技术（STEPCAM）来估计基于生态位和中性过程对社区组装的贡献。与我们的预期相反，我们的研究结果表明，随机过程，而不是基于生态位的过程，负责大多数慈鲷群落组装。我们还发现，基于生态位和中性过程的相对重要性在不同环境中是恒定的。然而，我们发现环境变化，社区性状的手段，和社区组成之间的显着关系。这些关系是由基于生态位的过程引起的，因为它们在模拟的、纯粹中立的社区中消失了。重要的是，这些结果可以潜在地调和文献中关于基于生态位或基于中性的过程在社区组装中的重要性的看似相反的发现，因为我们表明，在几乎（但不完全）中性组装的社区中已经可以发现显著的特质关系;也就是说，即使是对中性的微小偏离也会对社区模式产生重大影响。
The cichlid family features some of the most spectacular examples of adaptive radiation. Evolutionary studies have highlighted the importance of both trophic adaptation and sexual selection in cichlid speciation. However, it is poorly understood what processes drive the composition and diversity of local cichlid species assemblages on relatively short, ecological timescales. Here, we investigate the relative importance of niche‐based and neutral processes in determining the composition and diversity of cichlid communities inhabiting various environmental conditions in the littoral zone of Lake Tanganyika, Zambia. We collected data on cichlid abundance, morphometrics, and local environments. We analyzed relationships between mean trait values, community composition, and environmental variation, and used a recently developed modeling technique (STEPCAM) to estimate the contributions of niche‐based and neutral processes to community assembly. Contrary to our expectations, our results show that stochastic processes, and not niche‐based processes, were responsible for the majority of cichlid community assembly. We also found that the relative importance of niche‐based and neutral processes was constant across environments. However, we found significant relationships between environmental variation, community trait means, and community composition. These relationships were caused by niche‐based processes, as they disappeared in simulated, purely neutrally assembled communities. Importantly, these results can potentially reconcile seemingly contrasting findings in the literature about the importance of either niche‐based or neutral‐based processes in community assembly, as we show that significant trait relationships can already be found in nearly (but not completely) neutrally assembled communities; that is, even a small deviation from neutrality can have major effects on community patterns.