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往往通过影响扩散与基因流，塑造种群连通性的空间格局。以往针对景观对生物移动的影响评估多聚焦于单一物种，但当前保护领域日益普及的多物种管理策略，亟需基于多物种的研究推断予以支撑。本研究对比了美国东北部两种两栖动物的空间遗传格局，并量化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、物候特征及位点保真度等诸多生态属性上存在共性，但本研究假设，二者在移动模式与生活史方面的关键差异，会导致各自形成独特的遗传格局。本研究利用14个微卫星位点（microsatellite loci），针对22处繁殖池塘的两种两栖动物，检验了二者遗传分化水平的差异；同时通过构建32种景观阻力模型（landscape resistance models），评估了8种景观特征的影响效应。研究结果显示，斑点钝口螈的遗传分化水平显著高于林蛙。不同景观特征被分别鉴定为两个物种遗传格局的潜在驱动因子，且二者得到模型支持的驱动因子几乎无重叠。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互作方式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（A. maculatum）和林蛙（R. sylvatica）在移动能力及生活史方面的关键差异相一致。本研究结果强调，在评估景观基质对种群连通性的影响时，即使针对同一生境中生态特征相似的物种，也需要考虑多个物种的响应，这一点至关重要。