Data from: Cityscape genetics: structural versus functional connectivity of an urban lizard population

Functional connectivity is essential for the long-term persistence of populations. However, many studies assess connectivity with a focus on structural connectivity only. Cityscapes, namely urban landscapes, are particularly dynamic and include numerous potential anthropogenic barriers to animal movements, such as roads, traffic or buildings. In order to assess and compare structural connectivity of habitats and functional connectivity of gene flow of an urban lizard, we here combined species distribution models (SDMs) with an individual-based landscape genetic optimization procedure. The most important environmental factors of the SDMs are structural diversity and substrate type, with high and medium levels of structural diversity as well as open and rocky/gravel substrates contributing most to structural connectivity. By contrast, water cover was the best model of all environmental factors following landscape genetic optimization. The river is thus a major barrier to gene flow, while of the typical anthropogenic factors only buildings showed an effect. Nonetheless, using SDMs as a basis for landscape genetic optimization provided the highest ranked model for functional connectivity. Optimizing SDMs in this way can provide a sound basis for models of gene flow of the cityscape, and elsewhere, while presence-only- and presence-absence-modelling approaches showed differences in performance. Additionally, interpretation of results based on SDM factor importance can be misleading, dictating more thorough analyses following optimization of SDMs. Such approaches can be adopted for management strategies, e.g. aiming to connect native common wall lizard populations or disconnect them from non-native introduced populations, which are currently spreading in many cities in Central Europe.

功能连通性对于种群的长期存续至关重要。然而，现有多数相关研究仅聚焦于结构连通性开展连通性评估。城市景观（Cityscapes）即城市生境，具有高度动态性，且存在诸多阻碍动物移动的人为潜在屏障，例如道路、交通设施与建筑物等。为评估并比较某城市蜥蜴物种的生境结构连通性与基因流功能连通性，本研究将物种分布模型（Species Distribution Models, SDMs）与基于个体的景观遗传学优化流程相结合。SDMs分析筛选出的关键环境因子为结构多样性与基质类型：高、中等级的结构多样性，以及开阔生境与岩石/砾石基质，对结构连通性的贡献度最高。与之相对，经景观遗传学优化后，水体覆盖度成为所有环境因子中表现最优的模型因子。由此可见，河流是基因流的主要屏障；而在典型人为因子中，仅建筑物对基因流产生影响。尽管如此，以SDMs为基础开展景观遗传学优化，仍可得到功能连通性表现最优的模型。此类基于SDMs的优化方法，可为城市景观乃至其他区域的基因流模型构建提供可靠基础；而仅存在记录建模法与存在-缺失记录建模法的建模表现存在差异。此外，仅基于SDMs因子重要性开展结果解读可能存在误导性，因此需在SDMs优化后开展更全面的分析。此类方法可应用于相关管理策略制定：例如，针对目前正在中欧诸多城市扩散的外来引入种群，连通本土普通壁蜥种群，或阻断本土种群与外来引入种群之间的基因交流。