US Geological Survey, Montana Cooperative Fishery Research Unit, Montana State University, Bozeman, MT 59717, USA.
Mol Ecol. 2010 Sep;19(17):3620-33. doi: 10.1111/j.1365-294X.2010.04655.x. Epub 2010 Aug 13.
This study examined the influence of landscape heterogeneity on genetic differentiation between migratory bull trout (Salvelinus confluentus) populations in Glacier National Park, Montana. An information-theoretic approach was used to compare different conceptual models of dispersal associated with barriers, different models of isolation by distance, and the combined effects of barriers, waterway distance, patch size, and intra- and inter-drainage distribution of populations on genetic differentiation between bull trout populations. The effect of distance between populations on genetic differentiation was best explained by partitioning the effects of mainstem and tributary stream sections. Models that categorized barriers as having a one-way effect (i.e. allowed downstream dispersal) or a two-way effect were best supported. Additionally, patch size and the distribution of populations among drainages influenced genetic differentiation. Genetic differentiation between bull trout populations in Glacier National Park is linked to landscape features that restrict dispersal. However, this analysis illustrates that modelling variability within landscape features, such as dispersal corridors, will benefit landscape genetic analyses. Additionally, the framework used for evaluating the effects of barriers must consider not just barrier presence, but also potential asymmetries in barrier effects with respect to the organism under investigation.
本研究探讨了景观异质性对蒙大拿州冰川国家公园洄游型虹鳟（Salvelinus confluentus）种群遗传分化的影响。本研究采用信息理论方法，比较了与障碍相关的不同扩散概念模型、不同的距离隔离模型，以及障碍、水道距离、斑块大小以及种群在流域内和流域间分布对虹鳟种群间遗传分化的综合影响。种群间距离对遗传分化的影响最好通过将干流和支流部分的影响分开来解释。分类障碍具有单向效应（即允许下游扩散）或双向效应的模型得到了最好的支持。此外，斑块大小和种群在流域间的分布也影响遗传分化。冰川国家公园虹鳟种群间的遗传分化与限制扩散的景观特征有关。然而，这项分析表明，对景观特征（如扩散走廊）内的变异性进行建模将有助于景观遗传分析。此外，评估障碍影响的框架不仅必须考虑到障碍的存在，还必须考虑到与所研究的生物有关的障碍效应的潜在不对称性。
