Biological invasions threaten biodiversity and human wellbeing, with developing tropical countries being more vulnerable. Despite the urgency to reduce impacts of invasions, management interventions are constrained by unavailability of timely information on invasive species occurrence, potential drivers, and restoration priorities. Generating this information at biogeographic scales can be costly, unless integrated with multi-objective biodiversity monitoring. Invasive plant monitoring is integrated with India’s national-scale tiger population assessment, wherein natural areas are sampled at 25 km² scale to inventory plants. In 2018, a total of 158,979 plots were sampled covering ~358,550 km². We used 206,393 locations of high concern invasive plants to model their distribution using socio-ecological covariates and identify potential drivers of invasions. Considering the invasion magnitude and financial constraints in management, we further identified priority restorations sites at national-scale to maximize biodiversity outcomes. High-concern invasive plants were recorded from ~254,880 km² (72% sampled area) and modelled to invade in total ~750,905 km² (66%) Indian natural systems. While open and deciduous ecosystems were the highest invaded by woody plants, areas with extreme climate and less anthropic pressure were least invaded. Since managing invasions across their range seemed futile due to costly (~13.5 billion USD for one-time management) and ineffective strategies, restoration priority was assigned to least invaded areas (11% protected areas, 23% multi-use) to maximize biodiversity returns. Synthesis and applications: India implemented national-scale invasive plant monitoring by integrating it with the umbrella project on tiger assessment. Embarking on this big data, we show that two-thirds of India’s natural areas are under multiple plant invasions, owing to the legacy of anthropogenic modifications. Our study offers a restoration priority model, empowering policymakers to devise adaptive strategies for restoring invaded biomes and maximizing biodiversity returns.

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