Dispersal risk of <italic>Galinsoga quadriradiata</italic> on the Qinghai-Xizang Plateau under climate change

Galinsoga quadriradiata is a widely adapted and rapidly spreading invasive agricultural weed. This study utilizes data on species occurrence and for 10 environmental variables to predict the distribution of suitable habitat for G. quadriradiata on the Qinghai-Xizang Plateau under current and future climate scenarios (2050s and 2070s) based on SSP126, SSP245, and SSP585. The Biomod2 package was used to construct an ensemble model integrating 12 individual models, with ArcGIS and R used to analyze habitat suitability and centroid migration trajectories. The ensemble model demonstrated excellent predictive performance, with AUC and TSS values of 0.989 and 0.928, respectively. Elevation (elev) and the Human Footprint Index (hf) were identified as the dominant environmental factors influencing species distribution. Under current climatic conditions, G. quadriradiata is mainly distributed in eastern Qinghai, southeastern Gansu, southeastern Sichuan, northwestern Yunnan, southeastern and central Xizang, and southwestern Xinjiang. The suitable habitat area of G. quadriradiata is expected to increase significantly under the future climate scenarios explored, with the centroid generally shifting to the southeast. This developmentmay threaten food security and ecological safety on the Qinghai-Xizang Plateau; thus, preventive and management measures should be implemented as soon as possible.