The impact of anthropogenic activities on the spatiotemporal dynamics of the forest of Dogo-Kétou has been studied in relation to climate change observed in southeastern Benin. Especially, this study has detected the changes in climate parameters in southeast Benin from 1954 to 2016 and in forestland use from 1986 to 2018. A climatic break was detected, and the annual and monthly rainfall and temperature averages, the rainfall indexes, the concentration of precipitation, the number of rainy days according to the World Meteorological Organization and the bioclimatic aridity indexes were assessed. A GIS analysis was also performed based on Landsat images from 1986, 2000 and 2018 to detect the dynamic of land use and land cover of the classified forest of Dogo-Kétou. Excel 2016, R_{x64 4.1.2}, Rclimdex₃₀₁, Khronostat_1.01 and ArcGIS were used. The rainfall series showed a break in 1969. The segment from 1954 to 1968 was a period of excess rainfall with an average of 1420.46 mm/year. The segment from 1969 to 2016 was a rainfall deficit period with a reduction of 12 to 37% of rainy days and an increase of dry days for 21.4 days/year. In this last segment, southeast Benin experienced trends of its climate towards a sub-arid and arid climate. The agglomerations and bare soil of the forest of Dogo-Kétou increased to an area almost double the size between 1986 and 2018. The tree and shrub savannas gained in space from 12.1% in 2000 to 38.9% in 2018 and the dense forest and wooded savannas regressed by 52.6% in 1986 to 36.1% in 2000 then to 4.3% of the forest area in 2018. The subequatorial climate of southeastern Benin is gradually evolving towards a dry climate. The dense forest in this area is also gradually disappearing, giving way to savannas. This transformation towards the savannas was due to anthropogenic actions whose effects were strongly accentuated by climate change in this part of Benin and West Africa.

Les espèces exotiques envahissantes (IAS) peuvent avoir un impact négatif sur la régénération forestière. Cette étude a pour objectif d’évaluer les impacts de Chromolaena odorata sur la régénération arborée dans des forêts secondaires, ainsi que les moyens de les contrôler à bas prix. Les données ont été recueillies dans 77 parcelles rectangulaires de 0,5 ha dans des forêts secondaires du district de la Lama (Bénin, Afrique occidentale). Dans chaque parcelle, on a mesuré le dbh d’arbres et rejets (de dbh ≥ 10 cm) avec un ruban métrique, compté le nombre de rejets et mesuré la densité de recouvrement avec un densitomètre. La couverture de C. odorata, l’IAS ciblée, a été estimée dans une échelle de 0 (absence) à 100 % (couvert fermé). Les taillis et rejets ont été catégorisés dans trois groupes en fonction de leurs besoins de lumière (pionnier, non-pionnier léger besoin, et tolérant à l’ombre). C. odorata, densité de recouvrement, densité d’arbres, surface terrière, diamètre principal et recouvrement moyen ont été comptés et utilisés comme variables. Des coefficients de corrélation bilatérale entre les variables ont été calculés. Une analyse de régression, utilisant des modèles linéaires généralisés dans le logiciel R pour mettre en corrélation les variables du nombre de taillis/rejets par catégorie, a montré que C. odorata était en train d’éviter à la fois le développement des semis et des rejets de toutes les espèces, indépendamment de leurs catégories de besoin de lumière. Cependant, le couvert fermé avait une corrélation négative avec le couvert de l’herbe et peut être un moyen biologique de contrôler les IAS dans des forêts secondaires et dégradées.

Benin is not a big forest country, and the sustainable management of forest relics and their resources is a priority for the managers. This study was conducted in the forest regions of Pob and Ktou located in Southeast Benin with the objective of characterizing the ethnobotanical forest species prioritized by the local populations for their different uses. Specifically, it aimed to identify the ethnobotanical priority species for conservation, characterize the ethnobotanical value of these priority species, and analyze the tree organ harvesting methods used for the sustainable management of the forest species. Data have been collected from 287 local populations investigated and on the specimens collected on the field, which allowed to identify the scientific name. The combination of the citation frequencies, the method of reproduction, the vulnerability scores, and the IUCN status of the species has allowed to identify five priority ethnobotanical species per forest. The software R_i386_3.5.1 has been used for the different analysis such as the calculation of the various frequencies and the correspondence factor analysis to show the relationships between socioethnic groups, organs used, and the categories of use. The priority species identified in the forest of Pob are Milicia excelsa, Khaya senegalensis, Anogeissus leiocarpa, Ceiba pentandra, and Adansonia digitata. The priority species identified in the forest of Dogo-Ktou are Vitellaria paradoxa, Prosopis africana, Pterocarpus erinaceus, Khaya senegalensis, and Anogeissus leiocarpa. This study has revealed 54 tree species gathered into 47 genera and 25 botanical families. Their different parts have been harvested for many kinds of utilization such as medicinal, commercial, feeding, medico-magic, and artisanal. The most commonly used organs were leaves, fruits, seeds, barks, roots, and wood. The harvesting methods include cutting poles, cutting twigs and branches to harvest leaves, debarking the trunk, felling trees for wood, cutting roots, picking and harvesting fruits and seeds, and harvesting of flowers. Cutting down trees and picking flowers, fruits, and seeds have been the methods of harvesting, which affect negatively regeneration of the tree populations. It is then important to sensitize the local people on the sustainable management of their forest resources through the conception and implementation of a project program focused on forest conservation.

This study examined the local perception on the climate changes and how these changes combined with anthropogenic pressures generated by the forms of use of the forest resources, impact the sustainability of the forests of Pobè and Dogo-Kétou in southeast Benin. The data were collected through an investigation of 148 and 139 local populations sampled respectively in the municipalities of Pobè and Kétou in the studied area. An interview guide and a structured research questionnaire were used to collect the data which were analyzed using the software Ri386 3.5.1. The mains results revealed that more than 98% of the local population living around these forests perceive the effects of climate change and anthropogenic activities are the main causes. The consequences of climate change from the social perception are diversified, such as the violent winds and the scarcity of rains. The prolonged droughts are also confirmed by 61% of local population in Kétou and 81% in Pobè. In these conditions, trees have a harder time of reproduction with a poor capacity of regeneration. The analysis of the vulnerability of these forests in relation to the use values (UV) revealed that the populations living near to Dogo-Kétou forest use so much the forest resources (UV>2.5) than those of Pobè (UV<2.5). So, moderate pressure was notified on Pobè forest. The forest of Dogo-Kétou is therefore more vulnerable than the forest of Pobè from the view of the pressures linked to the categories of uses relative to food, energy wood, service wood, non-timber forest products and medicinal use. For adaptation strategies, the local population revealed the enrichment of the forests by indigenous forest species (32% in Kétou and 19% in Pobè), the reforestation (76% in Kétou and 84% in Pobè) and the creation of private plantations (39% in Kétou and 57% in Pobè). However, the establishment of ethnobotanical family gardens, the reduction of wood consumption for energy to the detriment of domestic gas, sensitization, prayer (church and vodoun) are ways to better adapt a good resilience to climate change.Keywords: Climate change, adaptation strategies, reforestation, resilience, forests, Benin.

Data entered from the documents on the Biodiversity Atlas of West Africa. Benin. Tome 1. Volume 1