Data from: Identification of landscape features influencing gene flow: how useful are habitat selection models?

Understanding how dispersal patterns are influenced by landscape heterogeneity is critical for modelling species connectivity. Resource selection function (RSF) models are increasingly used in landscape genetics approaches. However, because the ecological factors that drive habitat selection may be different from those influencing dispersal and gene flow, it is important to consider their explicit assumptions. We calculated pairwise genetic distances among 301 Alaskan Dall’s sheep (Ovis dalli dalli) using an intensive sampling effort and 15 microsatellite loci. We used multiple regression of distance matrices to assess the correlation of pairwise genetic distance and landscape resistance derived from an RSF, and combinations of landscape features hypothesized to influence dispersal. Dall’s sheep gene flow was positively correlated with steep slopes, moderate peak normalized difference vegetation indices (NDVI), and open land cover. Whereas RSF covariates were significant in predicting genetic distance, the RSF model itself was not significantly correlated with Dall’s sheep gene flow, suggesting that certain habitat features important seasonally (rugged terrain, mid-range elevation) were not influential to breeding dispersal. This work underscores that consideration of both habitat selection and landscape genetics models in developing conservation strategies will ensure resources are managed to meet both the immediate survival needs of a species and allow for long-term genetic connectivity.

阐明景观异质性对扩散模式的调控机制，对物种连通性建模具有关键意义。资源选择函数（Resource Selection Function, RSF）模型正日益被应用于景观遗传学研究框架中。然而，驱动栖息地选择的生态因子与影响扩散和基因流的生态因子往往存在差异，因此明确考量两类模型的预设前提至关重要。我们通过高密度采样方案，利用15个微卫星位点，对301只阿拉斯加白大角羊（Ovis dalli dalli）的成对遗传距离进行了测算。本研究采用距离矩阵多元回归法，评估了成对遗传距离与基于RSF得到的景观阻力，以及被推测可影响扩散的各类景观因子组合之间的相关性。结果显示，阿拉斯加白大角羊的基因流与陡峭坡地、归一化差异植被指数（Normalized Difference Vegetation Index, NDVI）的中等峰值，以及开阔的土地覆被类型呈显著正相关。尽管RSF的协变量可显著预测遗传距离，但RSF模型本身与白大角羊的基因流并无显著相关性，这表明某些具有季节重要性的栖息地特征（如崎岖地形、中等海拔）对繁殖扩散并无显著影响。本研究强调，在制定物种保护策略时同时纳入栖息地选择与景观遗传学模型，可确保保护资源的配置既能满足物种的即时生存需求，又能维持长期的遗传连通性。