Detection of potential plant invaders and prevention priorities for a nature reserve in the Southern Pampas, Argentina

Invasive species pose significant threats to biodiversity and human society’s long-term sustainability, altering ecosystem processes and causing ecological and economic damage. This study addresses the challenge of managing invasive species in the Southern Buenos Aires Mountains (Argentina), a region characterized by its unique grassland ecosystems with limited protection. The research focuses on identifying and prioritizing invasive plant species that have not yet invaded but pose potential risks. To do this, we developed a system for ranking prevention priority (SRPP) that combines the criteria of potential impact and the difficulty of control in case of invasion. We selected 20 features related to biological features of the species, their area of origin and previous invasive history elsewhere, as well as feasibility of control. We surveyed the area around the reserve and detected 302 exotic plant species, with 63% classified as introduced or established, but not yet invading. The SRPP revealed that 24% of these species, including plants globally known for their invasiveness, such us Silybum marianum, Melia azedarach, and Cynodon dactylon, pose the highest prevention priority due to their significant potential impact and control difficulty. By providing a transparent, reproducible, and ecologically grounded method for assessing prevention priorities, this study offers a valuable tool for anticipating plant invasions. It represents a significant contribution to invasion ecology by shifting the focus toward proactive management in vulnerable ecosystems, where early intervention is critical for conserving native biodiversity and maintaining ecosystem function.