Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands.
Wageningen Environmental Research, Wageningen UR, Wageningen, The Netherlands.
PLoS One. 2018 May 24;13(5):e0197182. doi: 10.1371/journal.pone.0197182. eCollection 2018.
General colonization concepts consent that a slow process of microhabitat formation and subsequent niche realization occurs during early stages after new habitat is released. Subsequently, only few species are able to colonize new habitat in the early onset of succession, while species richness increases steadily over time. Although most colonization studies have been performed in terrestrial ecosystems, running water ecosystems are equally or even more prone to colonization after disturbance due to their dynamic nature. We question how invertebrate succession patterns reconcile with general colonization concepts. With this study we provide insight into the colonization process in newly created lowland stream trajectories and answer how within-stream bio- and functional diversity develops over time. Our results show a rapid influx of species, with a wide range of functional traits, during the first season after water flow commenced. During more than two years of regular monitoring, immigration rates were highest in autumn, marking the effects of seasonality on invertebrate dispersal. Biodiversity increased while abundance peaks of species alternated between seasons. Moreover, also days since start of the experiment explains a considerable part of the variability for taxa as well as traits. However, the relative trait composition remained similar throughout the entire monitoring period and only few specific traits had significantly higher proportions during specific seasons. This indicates that first phase colonization in freshwater streams can be a very rapid process that results in a high biodiversity and a large variety of species functional characteristics from the early onset of succession, contradicting general terrestrial colonization theory.
一般的定居概念认为，在新栖息地释放后的早期阶段，会发生一个微生境形成和随后的生态位实现的缓慢过程。随后，只有少数物种能够在演替的早期阶段殖民新的栖息地，而物种丰富度随着时间的推移而稳步增加。尽管大多数定居研究都是在陆地生态系统中进行的，但流水生态系统由于其动态性质，在受到干扰后同样容易或更易于定居。我们质疑无脊椎动物演替模式如何与一般的定居概念相协调。通过这项研究，我们深入了解了新创建的低地溪流轨迹中的定居过程，并回答了溪流内部生物和功能多样性随时间如何发展。我们的研究结果表明，在水流开始后的第一个季节，就有大量具有广泛功能特征的物种迅速涌入。在两年多的定期监测中，秋季的移民率最高，这标志着季节变化对无脊椎动物扩散的影响。生物多样性增加，而物种丰度峰值在季节之间交替出现。此外，实验开始以来的天数也解释了分类群和特征可变性的相当一部分。然而，整个监测期间相对特征组成仍然相似，只有少数特定特征在特定季节具有显著更高的比例。这表明，淡水溪流的第一阶段定居可能是一个非常迅速的过程，从演替的早期就导致了高生物多样性和大量物种功能特征的出现，这与一般的陆地定居理论相矛盾。
