Tropical forest frontier landscapes are subject to land use changes and different claims on land by various actors, often leading to trade-offs and a general decline in ecosystem services (ES) for local communities. However, few comprehensive ES studies have been done in such data-scarce frontier regions and they are limited in terms of area, land uses, and number and types of ES assessed. This doctoral thesis aimed to analyse how local stakeholders in Myanmar’s Tanintharyi Region can benefit from various ES and how these are associated to different factors such as land use, land tenure, market access, or population structures. Applying advanced modelling techniques, I used Bayesian networks to model the supply, demand, flow and final outcomes of nine ES: subsistence foods, commercial products, fuelwood, medicinal plants, biodiversity, climate regulation, water regulation, environmental education, and cultural identity. The models were developed in an iterative process and integrated existing spatial datasets, census data and qualitative data from focus group discussions and interviews with local communities, government representatives, researchers, civil society organizations and non-governmental institutions working on land issues in Tanintharyi. I linked the nine models to spatial data to map ES supply, demand, and flow for local stakeholders across the region. Finally, I combined these maps to identify supply/demand (mis)matches as well as accessibility that particularly affects local communities. The thesis highlights the value of mosaic landscapes and the crucial role of equitable land tenure in tropical forest frontiers for providing multiple ES and enhancing human well-being.