Long-term monitoring programs are fundamental to detect changes in ecosystem health and understand ecological processes. In the current context of increasing anthropogenic threats on marine ecosystems, understanding the dynamics and response of communities becomes essential. We used data collected over 14 years in the REBENT benthic coastal invertebrates monitoring program, at a regional scale in the North-East Atlantic, covering a total of 26 sites and 979 taxa. Four distinct habitats were studied: two biogenic habitats associated with foundation species in the intertidal and subtidal zones and two bare sedimentary habitats in the same respective tidal zones. We used community trajectory analysis (CTA), a statistical approach that allows for quantitative measures and comparisons of temporal trajectories of ecosystems. We compared observed community trajectories to trajectories simulated under a non-directional null model in order to better understand the dynamics of the communities, their potential drivers, and the role of the studied habitats in these dynamics. Despite strong differences in the community compositions between sites and habitats, the communities followed non-directional dynamics during the 14 years monitored, which suggested stability at the regional scale. However, the shape, size, and direction of the trajectories of benthic communities were more similar within than among habitats, also suggesting the influence of the nature of the habitat on community dynamics. Results showed a higher variability in community composition the first years of the monitoring in the intertidal bare habitat and confirmed the role of biogenic habitats in maintaining temporal stability. They also highlighted the need to apprehend the role of transient and rare species and the scale of observation in temporal beta diversity analyses. Finally, our study confirmed the usefulness of CTA to link observed trajectory patterns to fundamental ecological processes.

中文翻译：

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长期沿海大型底栖动物群落轨迹分析揭示了栖息地依赖的稳定性模式

长期监测计划是检测生态系统健康变化和了解生态过程的基础。在当前海洋生态系统人为威胁日益增加的背景下，了解社区的动态和反应变得至关重要。我们使用了 14 年来在东北大西洋区域范围内的 REBENT 底栖沿海无脊椎动物监测计划中收集的数据，涵盖了总共 26 个地点和 979 个分类群。研究了四个不同的栖息地：两个与潮间带和潮下带基础物种相关的生物栖息地和两个相同潮汐带的裸露沉积栖息地。我们使用了社区轨迹分析 (CTA)，这是一种统计方法，可以对生态系统的时间轨迹进行定量测量和比较。我们将观察到的群落轨迹与在非定向空模型下模拟的轨迹进行了比较，以便更好地了解群落的动态、它们的潜在驱动因素以及所研究的栖息地在这些动态中的作用。尽管地点和栖息地之间的群落组成存在很大差异，但在监测的 14 年中，群落遵循非定向动态，这表明区域范围内的稳定性。然而，底栖群落轨迹的形状、大小和方向在栖息地内部比在栖息地之间更相似，这也表明栖息地的性质对群落动态的影响。结果表明，在潮间带裸露栖息地监测的头几年，群落组成的变异性更高，并证实了生物栖息地在维持时间稳定性方面的作用。他们还强调需要了解短暂和稀有物种的作用以及时间 β 多样性分析中的观察规模。最后，我们的研究证实了 CTA 将观察到的轨迹模式与基本生态过程联系起来的有用性。