For centuries, rainfed lowland rice production associated to sugar palm (Borassus flabellifer) hedges planted in the paddy field bunds (RLR-SP) has been an emblematic cultural agroforestry system in the indianized Southeast Asian countries. But recent changes in communication infrastructure, commercialization, urbanization, private and state interventions are driving the rapid transformations of these multi-functional systems. In the absence of in-depth analyses documenting the socio-ecological impacts of such change on household livelihoods and landscapes, a case study on the transformations, over the past four decades, of one of the most sophisticated coastal RLR-SP agroforestry system was implemented in Sathing Phra peninsula, Southeastern Thailand. Chronological series of satellite images and ground truthing were used to characterize and quantify land use change during 1983-2015, and 120 interviews with concerned stakeholders were carried out to understand agro-ecological, social, and economic effects of the driving factors of change on their livelihood systems. We show a process of diversification of farming (and off-farm) activities along their gradual market integration, since the opening of bridges and all-weather roads linking the area to neighboring cities in the 80s. We found that the traditional RLR-SP agroforestry system survived, almost unscathed, a first series of agrarian change. It was characterized by attempts at introducing irrigated rice, shrimp farming small perennial tree plantations in the paddies, or converting deep-water rice areas into small-scale integrated farming systems. The much improved communication infrastructures, and lack of irrigation water to switch from the low and unstable RLR yields to higher-value cash crops, increased the mobility of family farm laborers. They sized wage-earning opportunities, in the village or in fast developing urban centers, and escaped the drudgery of tapping sugar palms, in increased numbers. But a ris