# Global Patterns and Future Dynamics of Four Invasive Cocklebur Species Under Climate Change: Contrasting Climatic and Anthropogenic Drivers

## TL;DR

This study maps the current and future spread of four invasive cocklebur species worldwide, showing how climate and human activities influence their distribution under climate change.

## Contribution

The study provides global-scale projections of four invasive cocklebur species' distributions under climate and socioeconomic scenarios, highlighting contrasting drivers and future shifts.

## Key findings

- Future suitable habitats for cocklebur species are projected to shrink, with the greatest decline for Xanthium chinense.
- Climate factors dominate for Cyclachaena xanthiifolia and Xanthium spinosum, while human activity is more influential for Xanthium italicum and Xanthium chinense.
- Centroid shifts suggest habitat suitability will move toward higher latitudes and elevations under warming scenarios.

## Abstract

Invasive plants are spreading rapidly worldwide, threatening ecosystems, agriculture, and biodiversity. Climate change and human activities contribute to this spread, but their influence differs among species. Here, we mapped the current and future potential distributions of four invasive cocklebur species worldwide and evaluated the roles of climate and human-related factors. These species mainly occur in temperate and subtropical regions of the Northern Hemisphere. Future projections suggest that suitable areas will generally shrink, although the extent of change varies among species. Climate is the dominant driver for some species, whereas human activities are more important for others. Our findings provide useful evidence for early warning and management of invasive cockleburs under future climate change.

Climate change, together with intensifying human activities, is reshaping global plant invasion dynamics and increasingly threatening ecosystem stability and biodiversity. Cockleburs are highly invasive weeds with strong ecological plasticity and dispersal capacity, causing widespread impacts on agricultural systems and native ecosystems. Here, we used the maximum entropy (MaxEnt) model to assess the current (2001–2020) and future (2021–2040, 2041–2060, and 2061–2080) potential distributions, key driving factors, and centroid shifts of four invasive cocklebur species—Cyclachaena xanthiifolia (=Iva xanthiifolia), Xanthium chinense, Xanthium italicum, and Xanthium spinosum—at the global scale under current climate conditions and three Shared Socioeconomic Pathway scenarios (SSP126, SSP245, and SSP585). Species occurrence records were integrated with climatic, topographic, and anthropogenic variables to project habitat suitability. Model performance was robust, with mean training and testing area under the receiver operating characteristic curve (AUC) values > 0.8 for all species and mean true skill statistic (TSS) values > 0.8 for three species (0.660 for Xanthium spinosum). Suitable habitats were jointly shaped by climatic and anthropogenic factors, although the dominant drivers differed among species. Cyclachaena xanthiifolia and Xanthium spinosum were primarily constrained by temperature and precipitation, whereas Xanthium italicum and Xanthium chinense were more strongly associated with human activity. At present, suitable habitat areas for Cyclachaena xanthiifolia, Xanthium chinense, Xanthium italicum, and Xanthium spinosum were 1196.92 × 104, 358.76 × 104, 888.34 × 104, and 1985.14 × 104 km2, respectively. Future projections indicated overall contractions in suitable habitat, with pronounced interspecific variation. Xanthium chinense showed the largest mean decline (−161.23 × 104 km2 relative to the present), whereas Cyclachaena xanthiifolia experienced the smallest reduction (−53.15 × 104 km2 on average). Centroid analyses further suggested overall shifts toward higher latitudes and elevations under warming scenarios. Despite uncertainties related to climate scenario variability and assumptions inherent in species distribution modelling, these findings provide quantitative evidence to support global invasion risk assessment and climate-adaptive management of invasive cockleburs.