Pichler Maximilian, Creer Simon, Martínez Alejandro, Fontaneto Diego, Renema Willem, Macher Jan-Niklas
Theoretical Ecology, University of Regensburg, Regensburg, Germany.
Molecular Ecology and Evolution Group, School of Natural and Environmental Sciences, Bangor University, Bangor, Gwynedd, UK.
Mol Ecol. 2025 Apr;34(8):e17733. doi: 10.1111/mec.17733. Epub 2025 Mar 20.
Understanding the processes that shape community assembly is a critical focus of ecology. Marine benthic meiofauna, microscopic invertebrates inhabiting sediment environments, play important roles in ecosystem functioning but have been largely overlooked in metacommunity studies due to the lack of community data. In this study, we quantify the relative contributions of environmental filtering, spatial processes, and biotic associations in structuring meiofaunal communities. We applied Generalised Dissimilarity Modelling (GDM) and Joint Species Distribution Modelling (JSDM) to an extensive metabarcoding dataset comprising 550 samples collected from sandy beaches along over 650 km of the Dutch and German North Sea coast. Our findings reveal that biotic associations, followed by environmental factors, particularly the distance from the low tide line and sediment grain size, are primary drivers of meiofauna community turnover, highlighting the influence of sharp environmental gradients. Spatial factors indicating dispersal limitations have no major impact on community composition, supporting the assumption that microscopic organisms have strong dispersal capabilities. JSDM results demonstrate that while species sorting is a key driver of community assembly, environmental factors are most important in environmentally distinct ('extreme') sites, whereas biotic associations significantly shape community assembly in both environmentally similar and dissimilar habitats, emphasising the need to incorporate species interactions into models of community assembly. By providing insights into the drivers of meiofaunal community structure, our study highlights the importance of environmental gradients and biotic associations in shaping biodiversity patterns and underscores the potential for similar approaches to enhance understanding of other ecosystems with small, highly diverse, but understudied taxa.
了解塑造群落组装的过程是生态学的一个关键重点。海洋底栖小型动物是栖息在沉积物环境中的微观无脊椎动物，在生态系统功能中发挥着重要作用，但由于缺乏群落数据，在元群落研究中基本被忽视。在本研究中，我们量化了环境过滤、空间过程和生物关联在构建小型动物群落结构中的相对贡献。我们将广义差异建模（GDM）和联合物种分布建模（JSDM）应用于一个广泛的元条形码数据集，该数据集包含从荷兰和德国北海沿岸650多公里的沙滩上采集的550个样本。我们的研究结果表明，生物关联，其次是环境因素，特别是与低潮线的距离和沉积物粒度，是小型动物群落周转的主要驱动因素，突出了急剧环境梯度的影响。表明扩散限制的空间因素对群落组成没有重大影响，支持了微观生物具有强大扩散能力的假设。JSDM结果表明，虽然物种分选是群落组装的关键驱动因素，但环境因素在环境不同（“极端”）的地点最为重要，而生物关联在环境相似和不同的栖息地中都显著塑造了群落组装，强调了将物种相互作用纳入群落组装模型的必要性。通过深入了解小型动物群落结构的驱动因素，我们的研究突出了环境梯度和生物关联在塑造生物多样性模式中的重要性，并强调了采用类似方法增强对其他具有小型、高度多样但研究不足的分类群的生态系统理解的潜力。
