Fine-scale genetic analyses reveal invasion dynamics and management opportunities in a mountain basin for an avian-dispersed shrub

In studies of biological invasions, genomic data reveal introduction events, population structure and spatial expansion pathways, providing key insights to inform targeted and effective invasive species management. Fine-scale genetic studies elucidating the invasion processes remain scarce. This study investigates the local invasion dynamics of the avian-dispersed shrub Pyracantha angustifolia in a mountain basin of the Chaco Serrano, Córdoba, Argentina, integrating spatial distribution surveys with high-throughput RAD-sequencing genomic data. Sampling across an elevation gradient along a stream revealed species density decline with increasing elevation and distance from water, indicating recruitment hotspots near streams. Genetic analyses uncovered two distinct clusters with a patchy distribution, moderate differentiation and differing genetic diversity, suggesting at least two, genetically diverse, independent introductions. Kinship analyses revealed pervasive familial relationships within clusters but none between them, indicating fine-scale kin structure driven by localized dispersal and lack of post-introduction interbreeding between groups. Partial Mantel tests indicated a weak isolation-by-distance pattern at the landscape scale, while dispersal kernel modeling supported predominance of short-distance dispersal and occasional longer dispersal events. The findings provide practical data to improve ongoing management and control strategies to preserve the invaded ecosystem.