Spatial Distribution of Topmouth Gudgeonis Pseudorasbora parva Under Climate Change by Ensemble Models

Climate change may exacerbate biological invasion by expanding the distribution of invasive species. Pseudorasbora parva (Temminck & Schlegel, 1846) is a prevalent invasive fish species. It has posed significant threats to biodiversity and ecosystems in over 40 countries across Asia, Europe, and Africa. To avoid or mitigate its threats, it is necessary to evaluate its invasion risk. Species distribution models (SDMs), using occurrence data and bioclimatic factors, serve as critical tools for evaluating biological invasion risks. ANN, FDA, GAM, GBM, MARS, and RF are prominent individual algorithms. Ensemble models are generally considered better than individual algorithms as they can effectively reduce uncertainties. However, no study has yet used ensemble models to forecast the global distribution of P. parva under future climate change. Therefore, the aim of this study was to use ensemble SDMs, combined by above-mentioned six individual algorithms, to predict the global potential suitable habitats and influencing factors of P. parva under current and future climate change. Global occurrence data for P. parva were collected from online biodiversity platforms and literature databases. Bioclimatic variables were from WorldClim and ENVIREM. The results showed as follows: (1) The ensemble model demonstrated excellent performance with an AUC of 0.993; (2) The two bioclimatic factors exerting the most significant influence on P. parva distribution were the maximum temperature of the coldest month and isothermality, contributing 51.362% and 18.279% respectively; (3) The distribution of P. parva in the current period, as generated by the ensemble model, revealed that the primary invasion areas are concentrated at latitude 22°-55° N; (4) Future projections under various climate scenarios indicated an overall range expansion, with high-latitude or high-altitude regions becoming increasingly favorable. These findings suggest that the future global expansion trend of P. parva should not be ignored and effective management policies for its invasion should be provided.