Enhancing Invasive Alien Plant Species Management Through Participatory GIS: A Spatial Analysis of Species Distribution on Rodrigues Island, Mauritius

Invasive alien species (IAS) are a significant threat to ecosystems worldwide, in particular island ecosystems where ecological resilience is limited. Spatially explicit and locally informed strategies are crucial on small islands to effectively manage IAS. The present study uses an integrated approach to map and manage IAS on Rodrigues Island, Mauritius, using a combination of field surveys, participatory mapping, and spatial analysis tools. Field data was collected in four sites on Rodrigues, namely Cascade Pigeon, Cascade St Louis, Mourouk Valley, and Golden Bat Reserve, supported by participatory mapping and Inverse Distance Weighting (IDW) interpolation in ArcGIS. The results revealed firstly that invasion hotspots were concentrated in previously disturbed areas, especially in Mourouk Valley and Cascade Pigeon, where Furcraea foetida, Leucaena leucocephala, and Millettia pinnata co-occur. Secondly, grassland zones exhibited minimal invasion, indicating their potential as natural buffer zones for conservation. Thirdly, the integration of stakeholder knowledge through Participatory GIS (PGIS) enhanced the accuracy and contextual understanding of the spatial analysis. Fourthly, the IDW interpolation method demonstrated high precision with low root mean square error (RMSE) values and minimal spatial error (≤0.5 m). Finally, the study underscores the importance of adaptive, site-specific monitoring and management strategies that combine spatial tools and local knowledge. These findings provide a replicable framework for IAS management in other island ecosystems facing similar ecological challenges, contributing to national and international biodiversity conservation efforts, including Sustainable Development Goal 15—Life on Land.