Factors influencing the global invasion of the South American weedy species Praxelis clematidea (Asteraceae): a niche shift and modelling-based approach

Praxelis clematidea is a relatively unknown herb native to South America that has spread globally over the past four decades. In this study, we integrate ecological niche modelling (ENM) and niche shift analyses to understand its distribution, test niche conservatism hypotheses, and identify potential invasion sites under different climate change scenarios. In its native range, P. clematidea prefers climates with mild annual temperatures and winters. This species shows a great potential to continue spreading. Probable invasion sites include northern South America, Central America, India, Southeast Asia, and Africa. Future climate projections suggest increase of potential distribution in tropical regions and decrease in temperate areas. Niche conservatism was evident, although invaded areas in Asia and Australia showed slight niche expansion towards warmer climates, probably explained by ecological factors such as competition. Our results show that integrating occurrences from both native and invaded ranges in ENM models enhances predictability, even when niche is conserved. The combination of niche shift studies and ENM provides better insight into species invasion dynamics, resulting in the recognition of high-risk invasion areas that combined with the rapid access to new occurrences provided by citizen science platforms can result in early detection and lead to better management strategies.