Tropical forests are under pressure from both commercial and smallholder agriculture. Forest frontiers are seeing dynamic land use changes that frequently lead to land system regime shifts, posing challenges for the sustainability of entire local social-ecological systems. Monitoring highly dynamic land use change and detecting land system regime shifts is methodologically challenging due to trade-offs between spatial and temporal data resolution. We propose an innovative approach that combines analysis of very-high-resolution satellite imagery with participatory mapping based on workshops and field walks. Applying it in Laos, Myanmar, and Madagascar, we were able to collect annual land use information over several decades. Unlike conventional land use change mapping approaches, which assess only few points in time, our approach provides information at a temporal resolution that enables detection of gradual and abrupt land system regime shifts.

Tropical forest landscapes are undergoing vast transformations. Myanmar was long an exception to this trenduntil recent policy reforms put economic development at the forefront. Under ambiguous land rights, commercial agriculture has spread rapidly, causing an unprecedented loss of biodiversity-rich forest. In southeastern Myanmar, where land tenure is highly contested due to several decades of conflict, scientific evidence on these complex social-ecological processes is lacking. In the absence of past satellite data, we applied a participatory mapping approach and co-produced annual land use information with local land users between 1990 and 2017 for two case study landscapes. Results show that both landscapes have undergone a land use regime shift from small-scale farmers' shifting cultivation to plantations of rubber, betel nut, cashew, and oil palm. These changes are likely to have long-term impacts on land users' livelihoods and the environment. We call for a reconsideration of land governance arrangements and concerted land use planning that respects the rights of local land users and strengthens their role as environmental stewards. Applied with careful facilitation, participatory mapping could be an important tool to engage communities in the highly challenging process of transforming land governance to achieve more sustainable outcomes in this post-conflict context.