Remote sensing assessment of invasive plant species impacts on microclimate and water stress in mediterranean coastal ecosystems

This study uses multi-source, multi-temporal remote sensing imagery to compare the effects of invasive Heterotheca subaxillaris and Acacia saligna and natural vegetation on microclimate conditions in Israeli coastal plain. The overall accuracy of the classification and mapping of invasive species and other land covers was 85 %, with optimal performance observed using late autumn imagery. Among the natural areas, 45 % were occupied by native vegetation, 30 % by H. subaxillaris, 15 % by A. saligna and 10 % by bare soil/sand. Quantitative analysis revealed that H. subaxillaris, consistently elevated surface temperatures by 0.6 °C in spring, 1.8 °C in summer and 2.19 °C in autumn compared to native vegetation. This species also increased water vapor and potential evapotranspiration, while reducing soil evaporation and vegetation shading, resulting in both direct and indirect contributions to water stress. In contrast, A. saligna, provided localized cooling due to high vegetation density and shading, yet its high assimilation and transpiration rates led to elevated water vapor, daily total evaporation and PET indirectly amplifying water stress. Native vegeation moderated the local microclimate by decreasing temperature and water vapor, while maintaining stable evapotranspiration and low water stress throughout the dry season. This study highlights the complex interactions between invasive species and microclimate conditions, emphasizing the critical role of remote sensing techniques in monitoring and managing these species. By integrating remote sensing imagery with detailed microclimatic analysis, it provides novel insights into the contrasting ecological impacts of invasive species on temperature regimes, water stress, and evapotranspiration in Mediterranean coastal ecosystems.