Modeling the invasive potential of the opuntia cactus in arid ecosystems by assessing current and future distribution trends.

Invasive plant species threaten biodiversity, ecosystem stability, and agricultural productivity by outcompeting native flora and altering ecological processes. Opuntia ficus-indica is a highly invasive species that has established itself across arid and semi-arid regions due to its resilience to extreme environmental conditions and rapid vegetative propagation. This study employs ecological niche modeling (ENM) with MaxEnt to assess the current and future distribution of O. ficus-indica in Saudi Arabia. Occurrence records were compiled from field surveys, literature, and biodiversity databases. Occurrence records were compiled from field surveys, literature, and global biodiversity databases. Nineteen bioclimatic, ten soil, and three topographic variables were initially selected, and six key predictors were retained after multicollinearity reduction and Jackknife testing. Model performance was validated using the area under the curve (AUC) and partial ROC to ensure predictive accuracy. The most influential environmental predictors shaping its distribution were maximum temperature of the warmest month (bio5), NDVI, precipitation of the wettest month (bio14), mean temperature of the warmest quarter (bio10), soil organic carbon (SOC), and soil pH. The results indicate that the current distribution of O. ficus-indica is concentrated in southwestern Saudi Arabia, particularly in regions with moderate precipitation and temperature. Future climate projections (SSP245 and SSP585) suggest a northward and inland expansion, with increasing habitat suitability in Najran, Al Qassim, and central Riyadh, while certain highly suitable areas in the southwest may decline due to extreme warming. These findings highlight the potential ecological risks posed by climate-driven invasion and underscore the need for proactive management strategies. Integrated control measures, including mechanical removal, biological control, habitat restoration, and policy interventions, are recommended to mitigate its spread. This study provides a scientific basis for policymakers and conservationists to develop effective invasion management plans, ensuring the protection of native ecosystems in the face of climate change.