Modeling invasion patterns of Chromolaena odorata under changing climate and LULC in La Union, Philippines

Climate change and Land Use Land Cover (LULC) change may promote plant invasion, making the study of their impact on invasive alien species (IAS) crucial for environmental conservation. In this study, the invasive alien plant Chromolaena odorata was selected as the study species. The MaxEnt algorithm was employed to facilitate the Species Distribution Model (SDM) of C. odorata under current and future climate scenarios. Two emission scenarios of representative concentration pathways (RCP 2.6 and RCP 8.5) were considered for future climate conditions. The results showed good predictions from the MaxEnt model across the current scenario (area under the ROC curve (AUC) = 0.805), and future scenarios (AUC = 0.802 for RCP 2.6 and AUC = 0.807 for RCP 8.5). True Skill Statistics (TSS) scores indicated fair predictive performance with scores of 0.523 for current, 0.516 for RCP 2.6, and 0.501 for RCP 8.5. LULC affects the distribution of C. odorata in the Province of La Union, with ‘distance to built areas’ and ‘shrubland’ identified as the most important factors in shaping its potential distribution. Predictive results revealed a massive expansion of 23,279 ha of C. odorata under the RCP 2.6 scenario, and 29,106 ha under the RCP 8.5 scenario. The model results provide evidence of plant invasion and identify vulnerable habitats to C. odorata, supporting the development of evidence-based policies to prevent its spread. This study is the first to report the SDM of C. odorata influenced by LULC change and climate change in the province and across the Philippines.