Ecological Niche Divergence in an Invasive Non‐Native Shrub: Implications for Risk Assessments

ABSTRACT

Understanding how invasive species respond to distinct climatic conditions across their global distribution is essential for revealing the mechanisms underlying their ecological success. This study aimed to evaluate whether Nicotiana glauca , a widely distributed invasive shrub, conserves or shifts its realized climatic niche across different invaded regions. We compared the climatic niches of the species' native range (Argentina and Bolivia) with those of five invaded regions (North America, the Mediterranean, Northeast South America, Southern Africa, and Australia) using a PCA‐env framework. Our results show clear evidence of niche shifts in the Caatinga (Northeast Brazil) and Mediterranean regions, where N. glauca occupies warmer and more thermally stable environments in the Caatinga and cooler, more thermally variable climates in the Mediterranean, both with lower mean precipitation than the native range. These contrasting patterns indicate that the species expresses different portions of its fundamental climatic niche depending on the environmental context, reflecting a high degree of climatic plasticity. The ability of N. glauca to establish and persist under such distinct climatic regimes highlights its potential to invade areas beyond predictions based solely on native‐range conditions. These findings underscore the importance of considering climatic novelty and niche shifts when assessing invasion risks and developing predictive frameworks for species distribution.