Driving factors and impact of land-use change in a fragile rainfed lowland rice-sugar palm cultural agroforestry system in southern Thailand

The multi-functional agroforestry system associating rainfed lowland rice and sugar palm (RLR-SP) hedges has been sustaining emblematic cultural landscapes in the Indianized countries of Southeast Asia for centuries. Often established in areas facing very constrained soil–water conditions, it played a crucial role in the agro-ecological, social and economic resilience of these agrarian systems. Recent changes in communication infrastructure, commercialization, urbanization, state interventions and private initiatives have driven the transformations of these iconic cultural landscapes, but analyses of their socio-ecological impacts on household livelihoods and landscapes features are lacking. In this study, we quantified and analysed the transformations of a coastal RLR-SP cultural landscape in Southeast Thailand. We used remote sensing data to characterize and quantify land-use change during 1983–2015, and interviews with diverse stakeholders to understand the impacts of the driving factors of change on livelihood systems. After the mid-1980s, market integration facilitated by the construction of bridges and all-weather roads led to the diversification of farming and off-farm activities, increasing the mobility of farm labourers sizing wage-earning opportunities in neighbouring urban centres. In the 1990s, the RLR-SP system faced the introduction of an irrigation canal, shrimp farming, tree plantations, and the partial conversion of deep-water rice areas into mixed gardens. More recently, the demand for sugar palm fruits by the caning industry has revived an interest in sugar palm groves. A policy to raise the farm incomes associated with palm oil companies supported the conversion of paddy fields into small oil palm plantations, which is the most important recent land-use change and future threat to the survival of the RLR-SP system. Like in other Southeast Asian coastal areas, the increased frequency of extreme climatic events is another major threat faced by this emblematic but increasingly vulnerable cultural agroecosystem. The profitable and land/water resource efficient association of the RLR-SP system with commercial vegetable production on diversified smallholdings is a promising way towards a more sustainable landscape management that could be supported by improving on-farm water storage.