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Like other regions of Guinea Bissau, the economy of the Cacheu region is not very diversified and is dominated by cashew nut cultivation. As the country's leading production zone, with more than 30% of the national cashew nut production, the region has seen the disappearance of a large part of its natural ecosystems, especially the Elaeis guineensis parklands, despite their socio-economic importance. It is in this logic that this study is devoted to the analysis of the dynamics of the Elaeis guineensis parklands in the Cacheu region over the last fifteen years. To do this, terroir transects and mapping were carried out in order to identify and see the evolution of the landscape units. Surveys on the dynamics of the parklands and other landscape units have been carried out. The combination of these methods revealed a strong disappearance of Elaeis guineensis parklands and natural vegetation. Between 2003 and 2018, an average increase of 224 ha of cashew plantation by village terroir was noted, already causing the disappearance of 153.26 ha of Elaeis guineensis parklands on average. The main cause of this disappearance is the uncontrolled expansion of cashew nut plantations. In addition to this, there are many cuts of palm tree for house construction, habitat expansion, bad exploitation practices and climate deterioration. This pressure on Elaeis guineensis parklands is gradually leading them to disappear in favour of cashew nut monoculture. It is for this purpose that special attention is being paid to these ecosystems, which are of paramount importance to the livelihood of the local population.

In order to study the evolution of land use and the changes in land cover in Upper Casamance, from Landsat images acquired in 1987 and 2018, we used a method of multistage unsupervised classification. Recently developed to mapping and quantification of vegetation land cover changes in West-African coastal, this method is based on the following stages: first classification (K-means) over 15 classes, interpretation of the spectral signatures of the resulting classes followed by reclassification according to the chosen nomenclature, creation of thematic masks, classifications on masks, and finally reclassification. With the only difference, our study aims also to contribute, methodologically, to the knowledge of the spectral profiles of plant formation types. On a thematic level, the results show that between 1987 and 2018, forest areas decreased by 377,118.7 ha (or 27.4%), while wooded areas and agricultural and soil surfaces increased by 263,172.4 ha (or 19.1%) and 1560 75.5 ha (11.3%). In terms of change, deforestation by increasing agricultural and soil surfaces is noted along the border with the Gambia, savanization and anthropization is noted along the central part, and stability of forest surfaces followed by a slight increase in savannas and agricultural and soil surfaces is noted in the south.