Modeling spatial expansion of invasive alien species: relative contributions of environmental and anthropogenic factors to the spreading of the harlequin ladybird in France

摘要: Species distribution models (SDM) have often been used to predict the potential ranges of introduced species and prioritize management strategies. However, this approach assumes equilibrium between occurrences environmental gradients, an assumption which is violated during invasion process, where many suitable sites are empty because has not yet reached them. Here we considered invasive ladybird Harmonia axyridis as a case study show benefits using dynamic colonization-extinction model that does assume equilibrium. We multi-year occupancy incorporating environmental, anthropogenic neighborhood effects, identify factors explained spreading variation in France from 2004, when only few occupied were detected, 2011. found (urbanization, agriculture, vineyards, presence/absence highways) more diffusion process than (winter summer temperatures, wind-speed, rainfall). The surface urbanization was major factor increasing probability colonization. average temperature main affecting colonization, with negative effect high or low. revealed colonization mostly influenced by contributions coming radius 24 km around focal cell. contribution decreases over time, suggesting H. reaching its France. This confirmed small discrepancy observed performance our SDM predicting single year pattern at end period. Our advantage explicitly modelling state biological system spatial expansion identifying constraints. allows managers explore different actions on key moments hence providing powerful