An alien plant is considered invasive once it establishes self-sustaining populations and spreads extensively through regions outside its natural range (IPBES, 2019). The various stages involved in a plant invasion may be affected by climate, which can greatly influence its success (Theoharides and Dukes, 2007). Biological invasions are recognized as one of the most pressing global threats to biodiversity (Bellard et al., 2016; IPBES, 2019). Conservation priorities, such as biodiversity hotspots and protected areas, are particularly vulnerable to the establishment of invasive plants (Bellard et al., 2014; Li et al., 2016; Liu et al., 2020; Montti et al., 2021). Because eradication of invasive species is notoriously difficult and resource-intensive, predicting their potential spread is crucial for effective prevention management (Thuiller et al., 2005; Epanchin-Niell and Hastings, 2010). Although predictive models are increasingly being used, our understanding of how climate-related shifts may influence the potential distribution of invasive plant species at fine spatial scales remains limited.

Increases in temperature and atmospheric CO2, alongside changes in land use, are expected to facilitate the gradual process of ecological succession, enabling certain invasive plant species to become established and spread over time (Walther et al., 2009; Bellard et al., 2013). Consequently, climate change is expected to promote future invasions worldwide. Nevertheless, not all invasive species are predicted to expand their ranges under future climate conditions; some may instead undergo range contractions (Buckley and Csergő, 2017; Manzoor et al., 2021). Such divergent responses complicate the development of generalisable predictions and emphasize the importance of conducting species-specific assessments to guide prioritization of areas for invasion policy and management (Essl et al., 2011; Roy et al., 2014; McGeoch et al., 2016).

There is growing evidence that the effect of climate change on the potential distribution of invasive plant species varies greatly from region to region, resulting in different invasion outcomes, even when protected areas are considered (Bellard et al., 2013; Fulgêncio-Lima et al., 2021; Wan et al., 2021). Consequently, broad-scale global assessments may overlook critical local patterns of suitability for invasive plant species. Therefore, adopting a regional perspective when identifying the potential distribution of invasive plants is essential for designing geographically tailored prevention and management strategies. However, detailed spatial assessments of the current and future distributions of many high-impact invasive plants, especially in conservation-priority areas, are scarce (but see Montti et al., 2021).

South American tree tobacco (Nicotiana glauca R. Graham; Solanaceae) is considered one of the world’s 100 worst invasive species (Vélez-Gavilán, 2023). Native to north-west Argentina and southern Bolivia, it has successfully invaded diverse semi-arid environments across South America, North America, Europe, Africa and Australia (Ollerton et al., 2012; Issaly et al., 2024). Its ability to colonise semi-natural and natural habitats, ranging from sea level to 3,500 metres and spanning multiple continents, makes N. glauca a valuable case study. Furthermore, extensive research into the invasion biology of this species provides a solid foundation for understanding how it colonizes new areas and adapts to novel biotic and abiotic environments (Ollerton et al., 2012; Issaly et al., 2020; García et al., 2020; Costa et al., 2023; Issaly et al., 2024; Ferreras et al., unpublished data). Despite there being strong evidence of the species’ adaptive potential and ecological impact, its current and future climate-driven distribution remains uncertain.

In order to estimate the potential distribution of the invasive plant N. glauca under present and future climate scenarios, we employed ecological niche modelling (ENM), focusing particularly on biodiversity conservation areas within a spatial assessment of biogeographic realms. Specifically, we address the following questions: (a) What is the current potential global and regional range of N. glauca? (b) How might climate change alter its future distribution in different regions? and (c) To what extent does the species predicted range overlap with biodiversity hotspots and protected areas under current and future environmental conditions across biogeographic realms?

Our findings shed light on the potential distribution of N. glauca under current and future climatic conditions, and on the suitability of biodiversity conservation areas for this highly invasive species. This information is essential for guiding conservation priorities and strengthening biosecurity efforts (Essl et al., 2011; Roy et al., 2014).

Ecological niche models that use biologically relevant predictors can provide a more accurate estimation of species’ potential distributions by capturing how climate shapes their environmental limits. For N. glauca, which inhabits warm, arid environments, temperature variables reflect growth limits and tolerance of thermal extremes, while precipitation variables capture water availability and drought exposure. Its germination responses are known to be influenced by local temperature and water availability in both its native and invaded ranges (Ferreras et al., unpublished data). Using these biologically informed variables, our projections under current climatic conditions indicate that N. glauca could potentially occupy a wide range of suitable areas worldwide. These include its native range and the regions it has already invaded in North and South America, southern Africa, Australia, and Mediterranean Europe. We also identify climatically suitable areas in East Asia and North Africa where the species is not currently reported as present or invasive. Notably, this potential distribution closely resembles that of the invasive woody plant Ligustrum lucidum, native to East Asia (Montti et al., 2021). The absence of N. glauca from certain climatically suitable regions may be due to dispersal limitations, biotic resistance, invasion lags, or under-reporting associated with socio-economic and political factors (Gurevitch et al., 2011; Shackleton et al., 2019). Nevertheless, our findings suggest that N. glauca could colonize new areas that are potentially suitable but where it is not yet established. Its capacity for rapid adaptation to novel biotic and abiotic conditions (Issaly et al., 2020; García et al., 2020; Costa et al., 2023; Ferreras et al., unpublished data) could facilitate further invasions in the future. Consequently, preventive measures and trade regulations should be prioritized in these regions (Roy et al., 2024).

As reported for other invasive plant species (Hellmann et al., 2008), future climatic changes are expected to alter the potential distribution of N. glauca. Our predictions of reduced overall habitat suitability under global warming scenarios suggest that favourable climatic conditions for the establishment of this species may become increasingly limited in the long term. This pattern may be linked to a shift toward colder, drier, and less seasonal climates, which has been hypothesized to occur in parallel with its invasion history (Issaly et al., 2024). Although a potential contraction of N. glauca’s range could be interpreted as positive, the species may still expand by shifting its climatic niche within invaded regions (Issaly et al., 2024) and by rapidly adapting to novel biotic and abiotic conditions (Issaly et al., 2020; García et al., 2020; Costa et al., 2023; Ferreras et al., unpublished data). Moreover, several regions are projected to remain climatically stable, allowing the species to persist where it is already established. A notable poleward shift in suitable areas is anticipated, particularly in the Northern Hemisphere, where warming and subsequent drying are expected to meet the species' climatic requirements. The projected expansion of suitable habitats in the Palearctic and Nearctic realms aligns with patterns reported for other invasive plants (Wan et al., 2021; Nair et al., 2024). In the Southern Hemisphere, South America is the only continent expected to experience a marked increase in suitability, especially in central and southern regions east of the Andes. Our findings indicate that conservation planning should prioritize regions in northern Europe, central Asia, central North America, and southwestern South America, where climatic conditions are projected to become increasingly favourable for the species. Nonetheless, projections for Asia should be interpreted cautiously, as these areas include non-analogous climates that may increase model uncertainty.

Although biodiversity hotspots and protected areas are essential for conservation, they are increasingly threatened by plant invasions, even in remote or relatively undisturbed environments (Foxcroft et al., 2017; Montti et al., 2021). Our research revealed that a significant proportion of these areas, particularly in the Nearctic, Afrotropical and Australasian regions, currently provide suitable habitats for N. glauca. Furthermore, habitat suitability within biodiversity conservation areas in the Palearctic realm is projected to increase under future climate scenarios. This is of particular concern given the rapid growth of this invasive plant and its capacity to form dense stands that displace native vegetation (Vélez-Gavilán, 2023). To safeguard the ecological integrity of these priority areas, integrated management strategies, including early detection, habitat restoration, biosecurity measures, and community engagement, are urgently needed (Kumschick et al., 2015). Integrating our global and regional findings enables us to identify the specific regions where biodiversity hotspots and protected areas should be prioritized for early detection and control of N. glauca, both currently (i.e. southern and eastern Africa, southern Australia, and southern North America) and in the future (i.e. northern Europe).

In conclusion, our study suggests that N. glauca has the potential to spread beyond its current range into unoccupied areas where climatic conditions are suitable. Although this invasive species is not expected to expand globally under future climate scenarios, our projections indicate that climatically suitable conditions will increase at higher latitudes, particularly in the Northern Hemisphere across the Palearctic and Nearctic realms. Notably, a substantial proportion of biodiversity hotspots and protected areas worldwide are already suitable for N. glauca, and those located in the Palearctic realm are projected to become increasingly favourable in the future. Our study provides crucial spatial information that can be used to prevent and control this highly invasive plant more effectively. Furthermore, it highlights the importance of incorporating regional assessments into invasion risk analyses to enhance conservation planning.

During the preparation of this work the author(s) used ChatGPT and DeepL for language editing to improve the readability of some paragraphs. After using these tools, the author(s) reviewed and edited the content as needed and take(s) full responsibility for the content of the publication.

This work was supported by the National Ministry of Science and Technology (FONCYT-PICT-2018-0890 to A.N.S and FONCYT—PICT 2019-3633 to V.P.)