Utilization of IGN historical aerial photographs and Google earth for measuring changes in land use and evolution of termite lenticular mound abundance in paddy fields in Cambodia

Abstract This study was conducted to investigate termite mounds' dynamics in paddy fields in Cambodia. Historical aerial images collected in the 50s by the French Institut Géographique National (IGN) and recent Google Earth (GE) were analysed to study land use changes and mound distribution in 30 plots. A significant decrease in the surface covered by scrublands and forests was measured (from 37% in 1953 to less than 2% in 2021). We observed that most mounds seen in the field in 2021 could also be seen in IGN and GE images (88.6%), indicating that mounds have a long lifespan but also that they can be built in less than 70 years. Mound density was neither influenced by the topography nor by the restructuring of the paddy field boundaries during the Khmer Rouge regime. However, areas that were more recently converted into paddy fields had more mounds compared to areas that were already paddy fields in 1953 (2.92 vs. 1.53 mounds ha −1 , respectively). Therefore, deforestation and other environmental changes have turned mounds into remnants of the forests that had almost completely disappeared. This highlights the importance of protecting these specific environments in a changing world facing a major crisis of biodiversity loss.