Vietnam and Tunisia are southern countries, which both knew a tumultuous history, especially marked by the French colonization. But they are different, first from climate viewpoint (tropical for the one, Mediterranean for the other). We intend to compare their landscape dynamics since the beginning of the 20th century. We will based our talk on results, we obtained at local scale: Thua Thien-Hue province in Central Vietnam; the coastal dunes of the Governorate of Bizerte in northern Tunisia. The land use dynamics were mapped thanks to maps, satellite images and aerial photographs. We also conducted field studies and interviews with local people and forest managers. We will show that, beyond climate differences, common points can be identified in terms of anthropogenic pressure and its links with risks. With a time difference, both countries knew a decline of their forest area, due to a strong pressure. The inhabitants, poor, needed forest resources for their survival and forests represented a land reserve. The consequence was an increase of poor ecosystems: spatial extension of savannahs in Vietnam, dunes moving in Tunisia. By destroying their environment, people put themselves at risk. In fact, due to the forests decline, risks increase and threaten the local population. Soil erosion is stronger, floods become more dramatic and fires are more frequent and important. The growth of the exposed population increases more again risks. In Tunisia, these ones were perceived at the beginning of the 20th century and the solution was to reforest dunes. The positive effects are now visible and encourage to continue in this direction. In Vietnam, the main plantation programs were launched from 1990’s. Ambitious, they now concern considerable areas. Today, both countries know an increase of their forest area. They can serve as examples as forest plantations are encouraged worldwide to mitigate climate change.