Invasive species, such as the mainly aquatic African clawed frog Xenopus laevis, are a main threat to global biodiversity. The identification of dispersal corridors is necessary to restrict further expansion of these species and help to elaborate management plans for their control and eradication. Here we use remote sensing derived resistance surfaces, based on the normalised difference vegetation index (NDVI) and the normalised difference water index (NDWI) accounting for behavioural and physiological dispersal limitations of the species, in combination with elevation layers, to determine fine scale dispersal patterns of invasive populations of X. laevis in Portugal, where the frog had established populations in two rivers. We reconstruct past dispersal routes between these two invaded rivers and highlight high risk areas for future expansion. Our models suggest terrestrial dispersal corridors that connect both invaded rivers and identify artificial water bodies as stepping stones for overland movement of X. laevis. Additionally, we found several potential stepping stones into novel areas and provide concrete information for invasive species management.

中文翻译：

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预测入侵葡萄牙的非洲爪蛙Xenopus laevis的陆地扩散走廊

入侵物种，例如主要是水生非洲爪蛙Xenopus laevis，是对全球生物多样性的主要威胁。必须确定散布走廊，以限制这些物种的进一步扩大，并帮助拟订控制和根除这些物种的管理计划。在这里，我们根据归一化差异植被指数（NDVI）和归一化差异水指数（NDWI）（考虑物种的行为和生理扩散限制），结合海拔高度层，使用遥感衍生的阻力面来确定精细尺度的扩散葡萄牙的X. laevis入侵种群的分布模式，青蛙在两条河流中建立了种群。我们重建了这两条入侵河流之间过去的分散路线，并强调了高风险区域，以供将来扩展。我们的模型提出了一条陆地扩散走廊，该走廊连接了两条入侵的河流，并将人工水体确定为X. laevis陆上运动的垫脚石。此外，我们发现了一些进入新领域的潜在踏脚石，并为入侵物种管理提供了具体信息。