Pterocarpus erinaceus is a native tree species of the Guineo-Sudanian and Sudano-Sahelian zones where natural stands are under constant pressure and heavily exploited for timber, animal feeding and others uses. A part from the overexploitation, climate change could also become a serious threat to the species natural distribution. For that purposes, this study aims to assess the vulnerability of P. erinaceus potential niche to climate change within its natural distribution area in West Africa. Niche predictions are based on 6,981 natural occurrence of the species and 19 global bioclimatic variables available through WorldClim. The future niche of the species is predicted according to three concentration pathways (RCPs 2.6, 4.5 and 8.5) of BC model for 2050 and 2070, thanks to Maxent software. P. erinaceus is currently reported from Senegal to Cameroon. Its potential niche covers the Sudano-Sahelian zone and the Dahomey gap on approximately 17.42% of the total area of these countries. In general, the niche of the species is not sensitive to climate change, regardless of the climate scenario and the year. Compared to its initial niche, the niche of the species will increase from 22.33% to 43.61% in 2050 and from 27.12% to 53.61% in 2070. However, this ecological expansion observed mainly in the Gulf of Guinea, will be associated with a considerable decrease in the Sahel and central Nigeria. This study shows the importance of promoting the development of innovative silvicultural strategies for the extension and restoration of natural stands of P. erinaceus in order to meet sustainably the timber needs of the West African region. It helps also to strengthening the roles of natural forests in providing ecosystem services and mitigating climate change effects.

The expansion of African cities leads to the occupation of peripheral urban areas without respecting planning rules. The Greater Lomé (Togo) is no exception to this phenomenon of high-speed horizontal spreading, which causes recurrent flooding. The objective of this research is to understand the spatio-temporal changes in the dynamics of built-up areas in Greater Lomé. The methodology used is based on the analysis of Landsat images from the years 2007, 2012, 2016, and 2020 coupled with direct field observations and a literature review. The results showed an increase in residential areas to the detriment of the other land use/cover types. Estimated at 15,481 ha in 2007, the built-up area reached 35,521 ha in 2020, an increase of 33% to the detriment of vegetation and cultivation areas. This increase was marked by constructions in the floodplain of the Zio River. The field surveys revealed an increase in the density of most of the agglomerations. From 1863 ha in 2007, they increased to 14,485 ha in 2020, an increase of 12,622 ha or approximately 33%. These results indicate that attention needs to be paid to both the planning and control of the development of spaces in the outlying areas of Greater Lomé.

Pterocarpus erinaceus Poir (Fabaceae) is an endemic, highly exploited and threatened plant species in arid and semi-arid zones of West Africa. This study was conducted at the sub-regional level across three countries, namely Burkina Faso, Niger and Togo. These countries represent a spatial ecological gradient of P. erinaceus distribution to collect information on population structure and silviculture operating standards that could guide the industry, ensure species regeneration and establish appropriate management strategies for the species. Data were collected in P. erinaceus populations by means of forest inventories. Results showed that the average tree density was 1.17 ± 0.75 trees/ha in the Sahelian zone, 49.20 ± 63.2 trees/ha in the Sudanian zone and 110.9 ± 1.15 trees/ha in the Guinean zone. The average stem diameter values were 26.63 ± 7.89 cm (Guinean zone), 29.02 ± 15.44 cm (Sudanian zone) and 49.63 ± 19.44 cm (Sahelian) with noticeable variability (CV = 53.6%). Significant differences for these parameters were noted between the zones (P < 0.001). The average total height in the populations of the Sudanian zone (9.51 ± 2.75 m) were significantly less (P < 0.001) than in the other two zones (10.18 ± 2.27 m for the Sahelian zone and 14.16 ± 2.88 m for the Guinean zone). The merchantable heights were between 4.08 ± 1.35 m (Sahelian zone) and 3.63 ± 2.63 m (Guinean zone) and varied significantly from one zone to another (P < 0.001). The distribution of trees in diameter classes varied depending on the climate zone: modal distribution with most classes ranging from 30–65 cm in the Sahelian zone and 15–45 cm in the Sudanian zone and an “L” model distribution in the Guinean zone (most classes ranging between 10 and 25 cm), while the distribution of height classes showed a modal form for all climate zones. Two minimum diameters of exploitation (MDEs) could be determined: 35 cm for the Guinean and Sudanian zones (P = 316.6% and P = 53.4%, respectively) and 65 cm for the Sahelian zone (P = 111.9%) for a rotation period estimated at 20 years for all the climate zones.

Les îlots de forêts semi-décidues de la réserve de faune de Togodo constituent l’un des rares écosystèmes forestiers dans le paysage dénudé et fortement anthropisé de la plaine côtière du Sud Togo. L’analyse structurale de ces îlots forestiers a été réalisée au travers d’inventaires forestiers conduits dans 45 placettes. Dans chaque placette (625 m² de superficie), chaque individu ligneux (souche autonome dont le dbh ≥ 10 cm) a fait l’objet d’une détermination botanique et de mesure de ses caractéristiques dendrométriques. Les données recueillies ont permis d’établir un diagnostic sur l’état de conservation des espèces végétales de cette aire protégée. Au total, 73 espèces ligneuses ont été recensées avec une densité moyenne évaluée à 955 ± 303,1 N/ha et la surface terrière égale à 38,9 ± 18,9 m²/ha. La densité moyenne de la régénération a été estimée à 6465 N/ha. La répartition des espèces par mode de régénération montre que l’essentiel des espèces se régénère préférentiellement par semis (84,1 %), faiblement par rejets de souches (12,4 %) et rarement par drageonnage (3,5 %). La courbe exponentielle décroissante que révèle la distribution des individus en classes de diamètre indique que ces formations forestières ont subi une ou plusieurs dégradations et sont actuellement en cours de reconstitution, mais regorgent encore d’un grand potentiel en ressources forestières ligneuses. Les informations obtenues à travers cette étude constituent d’importantes bases techniques pour tester les indicateurs écologiques de gestion durable des forêts et fournissent des informations sur la mise en œuvre des directives de gestion pour la sauvegarde de cette aire protégée.

Since the 1960s, the countries of sub-Saharan Africa have been affected by an urban crisis due to the demographic explosion in cities and the resulting land pressure. These issues have resulted in the proliferation of spontaneous housing areas, which call the future of urban vegetation and its degree of inclusion in city planning into question. To analyze the current scientific knowledge on the development of urban landscapes, particularly in sub-Saharan Africa, a literature review on urban forestry covering the period of 1998–2022 was carried out in order to better guide future research works towards a greater consideration of urban forestry and its contribution to combating the adverse effects of climate change. Out of the 110 scientific papers selected, 50 were considered relevant because of their direct link with urban forestry. Based on the analysis of these papers, a classification of the articles according to five themes was carried out. These themes are the management of green spaces in urban areas, the functions of trees in an urban environment, the development of urban forestry, the characterization of urban tree flora, and the financing of urban forestry. Thus, the “function of trees in an urban environment and the characterization of urban tree flora” are the most addressed issues, being raised in 42% and 28% of articles, respectively. “Financing urban forestry” is practically not addressed (2%). The analysis of the 50 selected articles reveals a significant geographic concentration of urban forestry research. Countries such as South Africa, Kenya, and Ghana are more represented in the literature, while vast regions in Central and Western Africa (e.g., the Democratic Republic of Congo, Chad, and Niger) are the object of minimal or no documented research with regard to urban forestry. Future research should address these underrepresented themes, as they are crucial for the long-term sustainability of urban forestry projects. Particularly, research on financing mechanisms is essential to unlocking sustainable funding sources for urban forestry, a critical barrier to its expansion.

Land use and land cover (LULC) change remains a major concern in many countries. To examine how land is used for increased actions on forest landscape restoration (FLR) issues, this study analyses LULC changes from 1991 to 2022 and predict future patterns for the years 2050 in Tchamba Prefecture, Togo, using remote sensing and the Cellular Automata-Markov modelling technique. Results show that dense forests and gallery forests (18.85%), open forest/woodland (20.17%), and tree and shrub savannah (50.04%) were the predominant classes of the landscape in 1991. However, by 2022, most tree and shrub savannah had been converted to mosaic crop/fallow land (52.27%), open forest/woodland (19.32%), and plantation (7.09%). Thus, between 1991 and 2022, forest area decreased from 89.87% to 48.96%; a 45.52% reduction in coverage. Predictions are that open forest/woodland, tree and shrub savannah will decline, while mosaic crop/fallow land will increase (51.66%). However, slight increases were recorded in plantation (9.43%) and a slight balance in dense forests/gallery forests (16.17%). Consequently, forest area will slightly change between 2022 (48.96%) and 2050 (47.41%). These changes in LULC are associated to socio-economic pressures and political instability in the 1990s. So, the return to stability, the promotion of community forests as a key restoration model, and the valorisation of agroforestry species allows for the stabilisation of dense forests/gallery forests areas and an increase in plantation. Thus, it is therefore for all stakeholders involved in restoration processes to consider this information when planning FLR activities.