Data from: Urban landscape genetics: canopy cover predicts gene flow between white-footed mouse (Peromyscus leucopus) populations in New York City

In this study, I examine the influence of urban canopy cover on gene flow between 15 white-footed mouse (Peromyscus leucopus) populations in New York City. Nm calculated from F_ST and recent migration estimated in BayesAss+, but not historic migration estimated in Migrate-n, exhibited significant isolation-by-distance (IBD). Gene flow was also associated with “effective distances” between populations that were calculated based on percent canopy cover using two different approaches: 1) isolation-by-effective-distance (IED) that calculates the single best pathway to minimize passage through high-resistance (i.e. low canopy cover) areas, and 2) isolation-by-resistance (IBR), an implementation of circuit theory that identifies all low-resistance paths through the landscape. IBR, but not IED, models were still significantly associated with all three measures of gene flow after factoring out the influence of IBD using partial Mantel tests. In cases where both IBR and IED explained gene flow independently of IBD, an additional partial Mantel test indicated that the IBR models still explained gene flow after factoring out IED. The IBR models that explained the most variation in recent migration after factoring out IBD (r = 0.70 – 0.90) included landscape cells with at least 60-80% canopy cover as low resistance habitat. These results have implications for understanding the impacts of urbanization trends on native wildlife, as well as for urban reforestation efforts that aim to improve urban ecosystem processes.本研究探究了城市冠层覆盖度对纽约市15个北美白足鼠（Peromyscus leucopus）种群间基因流的影响。基于F_ST（遗传分化系数）计算得到的Nm（有效迁移个体数）以及通过BayesAss+估算的近期基因迁移量，而非Migrate-n所估算的历史基因迁移量，均呈现出显著的地理距离隔离（isolation-by-distance, IBD）信号。种群间的基因流同时与基于冠层覆盖百分比、通过两种不同方法计算得到的种群间“有效距离”相关：其一为有效距离隔离（isolation-by-effective-distance, IED），即计算出单条最优路径以最小化穿过高阻力（即低冠层覆盖）区域的路程；其二为抗性隔离（isolation-by-resistance, IBR），即通过电路理论（circuit theory）实现的、可识别景观中所有低阻力路径的方法。在通过偏曼特尔检验（partial Mantel tests）剔除地理距离隔离的影响后，抗性隔离模型仍与所有三类基因流指标呈显著相关，而有效距离隔离模型则无此关联。当抗性隔离与有效距离隔离均能独立于地理距离隔离解释基因流时，额外的偏曼特尔检验结果显示，在剔除有效距离隔离的影响后，抗性隔离模型仍可解释基因流模式。在剔除地理距离隔离的影响后，对近期基因迁移量变异解释度最高的抗性隔离模型（相关系数r=0.70~0.90），将冠层覆盖度至少为60%~80%的景观单元定义为低阻力生境。本研究结果有助于理解城市化趋势对本土野生动物的影响，同时也可为旨在优化城市生态系统功能的城市再造林工作提供理论参考。