International audience ; Along the edges of the Congo basin forest, where forest-savannah mosaics are the main ecological formation, it is important to determine how this mosaic has developed, particularly for forest protection. Have savannah lands resulted from deforestation or have forest patches expanded into them? Given the long-standing human occupation of this region, this question needs to be addressed through human-environment relationships over time. Combining oral histories of village mobility and geographical analyses of a forest-savannah mosaic in the Bolobo territory (Democratic Republic of Congo) can shed light on the landscape dynamics. This study involved nine months of daily participant observations of human land use practices, 40 individual interviews and 18 focus groups to analyse changing village mobility from the late 19th century to the present. Several maps were produced by combining oral histories of past village mobility with an evaluation of 44 GPS landmarks corresponding to former villages. Two Principal Component Analyses (PCA), based on landscape composition within a 250 m-radius buffer zone around the GPS landmarks, according to a land cover map classifying the landscape into 11 categories, were used to document forest expansion into old abandoned villages and the effect of distance from currently inhabited villages. Forest cover expanded into the abandoned villages and the savannah as a consequence of environmental eutrophication facilitating forest establishment. Forest use decreases with distance from currently inhabited villages as a result of a shift from semi-sedentary livelihoods in small settlements to entirely sedentary livelihoods in larger, extended villages. Livelihood transformations that took place during and after colonisation resulted in a decline in the quality of environmental goods and reduced the well-being of human populations. These insights can help NGO conservation and development efforts to be more sensitive to overlooked local human practices and needs. ; A ...