Plant invasion risk assessment in Argentina's arid and semi-arid rangelands

Climate change and anthropogenic activities have amplified the risk of invasive species spread. Approximately two-thirds of Argentina's land area comprises arid and semi-arid rangelands, yet the current state of invasions across these vast regions and their projected spread under future climate change scenarios remain insufficiently understood. To address this research gap, we employed an ensemble modeling approach to simulate and predict the distribution of 30 major invasive species across Argentina's five key arid and semi-arid rangelands. Our findings revealed that Patagonia and Western Chaco are minimally impacted by invasive species, while the Monte and Puna rangelands exhibit extensive areas of low invasion risk. In contrast, the Caldenal rangeland, as an ecotone, faces the most severe impacts. Notably, Centaurea solstitialis, Cynodon dactylon, Diplotaxis tenuifolia, Plantago major, Polypogon monspeliensis, Sorghum halepense, and Taraxacum officinale were identified as key invaders in Argentina's arid and semi-arid rangelands, with invasion areas exceeding 10% in at least one rangeland. Under high-emission scenarios, the invasion risk is projected to increase significantly across different rangelands. Among the key environmental variables incorporated into the model, the mean temperature of the driest quarter emerged as the most critical climatic variable due to its high contribution to the predicted distribution of 19 invasive species. Our study serves as a crucial warning for the management of arid and semi-arid rangelands in Argentina, highlighting the urgency of addressing invasive species under changing environmental conditions.