Data from: River network architecture, genetic effective size and distributional patterns predict differences in genetic structure across species in a dryland stream fish community

Dendritic ecological network (DEN) architecture can be a strong predictor of spatial genetic patterns in theoretical and simulation studies. Yet, interspecific differences in dispersal capabilities and distribution within the network may equally affect species’ genetic structuring. We characterized patterns of genetic variation from up to ten microsatellite loci for nine numerically dominant members of the upper Gila River fish community, New Mexico, USA. Using comparative landscape genetics, we evaluated the role of network architecture for structuring populations within species (pairwise FST) while explicitly accounting for intraspecific demographic influences on effective population size (Ne). Five species exhibited patterns of connectivity and/or genetic diversity gradients that were predicted by network structure. These species were generally considered to be small-bodied or habitat specialists. Spatial variation of Ne was a strong predictor of pairwise FST for two species, suggesting patterns of connectivity may also be influenced by genetic drift independent of network properties. Finally, two study species exhibited genetic patterns that were unexplained by network properties and appeared to be related to nonequilibrium processes. Properties of DENs shape community-wide genetic structure but effects are modified by intrinsic traits and nonequilibrium processes. Further theoretical development of the DEN framework should account for such cases.枝状生态网络（Dendritic Ecological Network, DEN）架构在理论与模拟研究中，可作为空间遗传格局的强有力预测因子。然而，网络内部的种间扩散能力差异与分布差异，同样会对物种的遗传结构造成影响。本研究针对美国新墨西哥州希拉河上游鱼类群落中的9个数量占优物种，利用至多10个微卫星位点（microsatellite loci）对其遗传变异格局进行了解析。本研究采用比较景观遗传学（comparative landscape genetics）方法，评估了网络架构对物种种内种群结构（两两FST, pairwise FST）的调控作用，并同时明确考量了种内种群动态对有效种群大小（effective population size, Ne）的影响。共有5个物种的连通性格局和/或遗传多样性梯度与网络结构的预测结果相符，这类物种多为小型物种或生境特化类群。对于2个物种而言，Ne的空间变异是两两FST的强有力预测因子，这表明连通性格局或许还会受到独立于网络属性的遗传漂变的影响。最后，另有2个研究物种的遗传格局无法通过网络属性进行解释，其相关机制似乎与非平衡过程有关。枝状生态网络的属性塑造了群落尺度的遗传结构，但其效应会受到物种内在性状与非平衡过程的调控。未来枝状生态网络框架的理论发展，应将此类情形纳入考量范围。