This study examines changes in medicinal and wild food plant knowledge in the Alpine Southern Occitan area, focusing on temporal and cultural shifts. Drawing from ethnobotanical data from the Maira Valley (1970, 2022), Stura Valley (2004), and Grana Valley (2011), we explore dynamics in plant use and how they may have been generated by ecological, socio-economic, and cultural changes. A total of 308 plant taxa were recorded, with notable declines in Asteraceae and Lamiaceae utilizations by 2022, suggesting a remarkable erosion of traditional ecological knowledge (TEK). Conversely, the use of families like Brassicaceae and Amaranthaceae increased, possibly due to socio-economic factors. This study also found in recent years a decrease in medicinal plant uses and a greater reliance on food system-related plants. Logistic regression models highlighted altitude (600-1600 masl) as a key factor in plant diversity use, with older participants showing more diverse ethnobotanical knowledge. This study underscores the resilience and transformation of plant knowledge in response to socio-economic and environmental changes in the Alpine area.