Biodiversity conservation planning is highly important in the current context of global change. Biodiversity conservation can be achieved by understanding changes in land use at the landscape scale. Such understanding is needed to reverse the unprecedented pressure on natural resources that has been reported by many studies conducted on biodiversity conservation within the Oti-Keran-Mandouri protected areas. Land cover maps reflecting different dates (1987, 2000, and 2013) and depicting different management systems, with overall accuracy ranging from 73% to 79%, were analyzed to understand the processes that lead to habitat degradation within these protected areas. The nature of change, within a given land cover class, was determined by comparing land cover maps on different dates using a decision tree algorithm that compares the number of patches, their areas, and their perimeters at different time periods (T₁ and T₂). Specifically, two time-periods were considered for this analysis: 1987–2000 and 2000–2013. Croplands and settlements increased at an average of 108.13% and 5.45%, respectively, from 1987 to 2000. From 2000 to 2013, croplands gained from all other land categories and continued to increase at a rate of 11.77% per year, whereas forests and savannas decreased at an annual average rate by 5.79% and 2.32%, respectively. The dominant processes of habitat change from 1987 to 2000 were the creation of forests, dissection of savannas, attrition of wetlands, and creation of croplands. Meanwhile, from 2000 to 2013, there was attrition of forests, as well as attrition of savannas, dissection of wetlands, and aggregation of croplands. In general, from 1987 to 2013, natural habitats regressed and were replaced by croplands; forests, savannas, and wetlands decreased at an average annual percentage 5.74%, 3.94%, and 2.02%, respectively, whereas croplands increased at an average annual rate of 285.39% of their own area. Aggregation, attrition, dissection, and creation were the main habitat change processes identified for the overall period from 1987 to 2013. There was habitat loss in forests and savannas and habitat fragmentation in wetland due to attrition and dissection, respectively. Identifying and understanding habitat change processes would enable the taking of appropriate biodiversity conservation actions.

Carbon stocks in forest ecosystems, when released as a result of forest degradation, contribute to greenhouse gas (GHG) emissions. To quantify and assess the rates of these changes, the Intergovernmental Panel on Climate Change (IPCC) recommends that the REDD+ mechanism use a combination of Earth observational data and field inventories. To this end, our study characterized land-cover changes and forest-cover dynamics in Togo between 1985 and 2020, using the supervised classification of Landsat 5, 7, and 8 images on the Google Earth Engine platform with the Random Forest (RF) algorithm. Overall image classification accuracies for all target years ranged from 0.91 to 0.98, with Kappa coefficients ranging between 0.86 and 0.96. Analysis indicated that all land cover classes, which were identified at the beginning of the study period, have undergone changes at several levels, with a reduction in forest area from 49.9% of the national territory in 1985, to 23.8% in 2020. These losses of forest cover have mainly been to agriculture, savannahs, and urbanization. The annual change in forest cover was estimated at −2.11% per year, with annual deforestation at 422.15 km² per year, which corresponds to a contraction in forest cover of 0.74% per year over the 35-year period being considered. Ecological Zone IV (mountainous, with dense semi-deciduous forests) is the one region (of five) that has best conserved its forest area over this period. This study contributes to the mission of forestry and territorial administration in Togo by providing methods and historical data regarding land cover that would help to control the factors involved in forest area reductions, reinforcing the system of measurement, notification, and verification within the REDD+ framework, and ensuring better, long-lasting management of forest ecosystems.

Au Togo, l'installation des ouvrages portuaires, la construction du barrage hydroélectrique de Nangbéto, la croissance urbaine et les activités relatives à l’installation des bassins piscicoles, et l'expansion des aires de production en agriculture sont les causes majeures de la dégradation drastique des mangroves. Afin de contribuer à une meilleure gestion de cet écosystème, une évaluation de la structure actuelle des mangroves, de leur dynamique spatio-temporelle et des enjeux socio-économiques a été réalisée. Pour ce faire, des données d'inventaires forestiers, d'entretiens dirigés et des images Landsat de 1986 et de 2014 ont été utilisées. Les inventaires ont permis de recenser 23 espèces végétales réparties en 23 genres et 17 familles dominées par les Rhyzophora racemosa et Avicennia germinans. La classification hiérarchique des relevés d'inventaire forestier a permis d’identifier trois groupements végétaux de mangroves. Les résultats des enquêtes montrent que tous les acteurs utilisent le bois provenant de la mangrove pour des besoins énergétiques et de service. De 1986 à 2014, l’état des unités d’occupation du sol de la zone d’étude a subi d'énormes mutations. Les zones inondables et les tannes ont vu leurs superficies augmentées respectivement de 39,91 % et 46,06 % tandis que le couvert de végétation dense a perdu globalement 47,19 % (soit 829,82 ha) de sa superficie. Les pressions anthropiques seraient à l'origine de la dégradation des mangroves, impactant les services écosystémiques ainsi que leur productivité. Du fait de l’importance écologique des mangroves, il est urgent et nécessaire d’élaborer un plan d’aménagement adéquat prenant en compte les réalités actuelles.