Alexandridis Nikolaos, Bacher Cédric, Desroy Nicolas, Jean Fred
DYNECO-LEBCO, IFREMER, Centre de Bretagne, Plouzané, France.
Laboratoire Environnement et Ressources de Bretagne Nord, IFREMER, Station CRESCO, Dinard, France.
PeerJ. 2018 Jun 18;6:e5038. doi: 10.7717/peerj.5038. eCollection 2018.
The complexity and scales of the processes that shape communities of marine benthic macroinvertebrates has limited our understanding of their assembly mechanisms and the potential to make projections of their spatial and temporal dynamics. Individual-based models can shed light on community assembly mechanisms, by allowing observed spatiotemporal patterns to emerge from first principles about the modeled organisms. Previous work in the Rance estuary (Brittany, France) revealed the principal functional components of its benthic macroinvertebrate communities and derived a set of functional relationships between them. These elements were combined here for the development of a dynamic and spatially explicit model that operates at two spatial scales. At the fine scale, modeling each individual's life cycle allowed the representation of recruitment, inter- and intra-group competition, biogenic habitat modification and predation mortality. Larval dispersal and environmental filtering due to the tidal characteristics of the Rance estuary were represented at the coarse scale. The two scales were dynamically linked and the model was parameterized on the basis of theoretical expectations and expert knowledge. The model was able to reproduce some patterns of α- and β-diversity that were observed in the Rance estuary in 1995. Model analysis demonstrated the role of local and regional processes, particularly early post-settlement mortality and spatially restricted dispersal, in shaping marine benthos. It also indicated biogenic habitat modification as a promising area for future research. The combination of this mechanism with different substrate types, along with the representation of physical disturbances and more trophic categories, could increase the model's realism. The precise parameterization and validation of the model is expected to extend its scope from the exploration of community assembly mechanisms to the formulation of predictions about the responses of community structure and functioning to environmental change.
塑造海洋底栖大型无脊椎动物群落的过程具有复杂性和规模性，这限制了我们对其组装机制的理解以及对其时空动态进行预测的能力。基于个体的模型可以通过让观察到的时空模式从关于建模生物的第一原理中浮现出来，从而阐明群落组装机制。此前在法国布列塔尼的朗斯河口开展的工作揭示了其底栖大型无脊椎动物群落的主要功能组成部分，并推导了它们之间的一组功能关系。在此，这些要素被结合起来，用于开发一个在两个空间尺度上运行的动态且具有空间明确性的模型。在精细尺度上，对每个个体的生命周期进行建模，可以表示补充、组内和组间竞争、生物栖息地改造以及捕食死亡率。在粗尺度上，则体现了由于朗斯河口潮汐特征导致的幼体扩散和环境过滤。这两个尺度动态相连，并且该模型是根据理论预期和专家知识进行参数化的。该模型能够重现1995年在朗斯河口观察到的一些α多样性和β多样性模式。模型分析表明了局部和区域过程，特别是定居后早期死亡率和空间受限扩散，在塑造海洋底栖生物方面的作用。它还表明生物栖息地改造是未来研究的一个有前景的领域。将这种机制与不同的底物类型相结合，以及对物理干扰和更多营养类别进行表示，可能会增加模型的真实性。预计对该模型进行精确的参数化和验证，将把其范围从群落组装机制的探索扩展到对群落结构和功能对环境变化的响应进行预测的制定。
