Data from: Divergent landscape effects on population connectivity in two co-occurring amphibian species

The physical and environmental attributes of landscapes often shape patterns of population connectivity by influencing dispersal and gene flow. Landscape effects on movement are typically evaluated for single species. However, inferences from multiple species are required for multi-species management strategies increasingly being applied in conservation. In this study, I compared the spatial genetic patterns of two amphibian species across the northeastern U.S. and estimated the influence of specific landscape features on observed genetic patterns. The spotted salamander (Ambystoma maculatum) and wood frog (Rana sylvatica) share many ecological attributes related to habitat use, phenology and site fidelity. However, I hypothesized that important differences in their movement patterns and life history would create distinct genetic patterns for each species. Using 14 microsatellite loci, I tested for differences in the level of genetic differentiation between the two species across 22 breeding ponds. The effects of eight landscape features were also estimated by evaluating 32 landscape resistance models. Spotted salamanders exhibited significantly higher genetic differentiation than wood frogs. Different landscape features were also identified as potential drivers of the genetic patterns in each species, with little overlap in model support between species. Collectively, these results provide strong evidence that these two amphibian species interact with the landscape in measurably different ways. The distinct genetic patterns observed are consistent with key differences in movement ability and life history between A. maculatum and R. sylvatica. These results highlight the importance of considering more than one species when assessing the impacts of the landscape matrix on population connectivity, even for ecologically similar species within the same habitats.

景观的物理与环境属性通常通过影响扩散（dispersal）与基因流（gene flow），塑造种群连通性（population connectivity）的格局。针对单一物种的景观对移动的影响评估已较为普遍，但保护领域日益推广的多物种管理策略，亟需基于多物种的推断结果作为支撑。
本研究对比了美国东北部两种两栖动物的空间遗传格局，并评估了特定景观特征对观测到的遗传格局的影响。斑点钝口螈（Ambystoma maculatum）与林蛙（Rana sylvatica）在栖息地利用、物候（phenology）以及位点保真度（site fidelity）等诸多生态属性上具有较高相似性。然而本研究假设，二者在移动模式与生活史方面的关键差异，会导致各自呈现独特的遗传格局。
本研究采用14个微卫星位点（microsatellite loci），针对横跨22个繁殖池（breeding ponds）的两个物种种群，检验了其遗传分化（genetic differentiation）水平的差异。同时，通过构建32种景观阻力模型（landscape resistance models），评估了8种景观特征的效应。
结果显示，斑点钝口螈的遗传分化水平显著高于林蛙。不同的景观特征被分别确定为两个物种遗传格局的潜在驱动因子，二者得到模型支持的驱动因子重叠度极低。
综合来看，这些结果提供了强有力的证据，表明这两种两栖动物与景观的相互作用存在可观测的显著差异。本研究观测到的独特遗传格局，与斑点钝口螈和林蛙在移动能力及生活史方面的关键差异相一致。
本研究结果凸显了：在评估景观基质对种群连通性的影响时，即便针对同一生境中生态特征相似的物种，也需要考虑不止一个物种的响应。