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.树状生态网络（Dendritic ecological network, DEN）结构在理论与模拟研究中可作为空间遗传格局的强预测因子。然而，物种间扩散能力的差异及其在网络内的分布格局，同样会对物种的遗传结构产生影响。我们针对美国新墨西哥州希拉河上游鱼类群落中9个种群数量占优的物种，利用至多10个微卫星位点（microsatellite loci）表征了其遗传变异格局。采用比较景观遗传学（comparative landscape genetics）方法，我们评估了网络结构对物种种群结构的塑造作用，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。其中5个物种的连通性格局与/或遗传多样性梯度符合网络结构的预测结果，这类物种多为体型偏小或生境特化类群。有效种群大小的空间变异可显著预测2个物种的两两FST（pairwise FST），这表明连通性格局或同时受到不受网络属性影响的遗传漂变的调控。另有2个研究物种的遗传格局无法通过网络属性得到解释，其似乎与非平衡过程（nonequilibrium processes）相关。树状生态网络的属性能够塑造群落尺度的遗传结构，但该效应会受到物种内在性状与非平衡过程的调控。未来针对DEN框架的理论拓展研究应将这类情形纳入考量。