L’importance de la végétation urbaine dans la production des services écosystémiques en général est largement démontrée. Mais la part des arbres d’alignement dans la diffusion des avantages socio-écologiques est rarement évoquée, malgré leur contribution remarquable au mieux-être des citadins. Le présent travail a pour objectif d’évaluer la contribution de la diversité floristique des rues aménagées dans la fourniture des biens et services aux résidents de la ville de Grand-Popo. La démarche méthodologique utilisée a permis de dénombrer des arbres plantés sur 10 kilomètres de rues aménagées et de questionner 164 ménages sur les services rendus par ces arbres. Les paramètres de diversité sont calculés pour apprécier la phytodiversité des axes routiers. La matrice des formes d’usages des organes est établie, avec une correspondance aux catégories de services écosystémiques existantes.  Les taux de réponses des organes utilisés par espèce sont soumis à un test de Chi 2 et à une analyse factorielle des correspondances pour déterminer la spécificité des espèces dans la fourniture des services écosystémiques. Les résultats obtenus révèlent 540 individus, répartis en 26 espèces et 17 familles le long des axes routiers de la ville de Grand-Popo. L’indice moyen de diversité de Shannon (3,61 ± 0,14 bits) et l’équitabilité de Pielou (0,76 ± 0,06) expliquent un phénomène de dominance de quelques espèces, dont la plus représentative est Cocos nucifera avec 20 % de l’effectif total des individus. Trois services écosystémiques (approvisionnement, régulation et socioculturel) sont attribués aux arbres urbains de la ville, avec une grande importance accordée à la fourniture de l’ombrage et à l’alimentation. Pour une valorisation de la foresterie urbaine, la prise en compte de ces informations pourrait servir à promouvoir les services écosystémiques sans compromettre la viabilité des arbres en plantations dans la ville de Grand-Popo.

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The vegetation cover of the Ouémé Delta constitutes a biodiversity hotspot for the wetlands in southern Benin. However, the overexploitation of natural resources in addition to the intensification of agricultural practices led to the degradation of the natural ecosystems in this region. The present work aims to reconstruct, using remote sensing, the spatial dynamics of land use in the Ouémé Delta in order to assess the recent changes and predict the trends in its vegetation cover. The methodology was based on remote sensing and GIS techniques. Altogether, this process helped us carry out the classification of Landsat images for a period of 30 years (stating year 1990, 2005, and 2020) via the Envi software. The spatial statistics resulting from this processing were combined using ArcGIS software to establish the transition matrices in order to monitor the conversion rates of the land cover classes obtained. Then, the prediction of the plant landscape by the year 2035 was performed using the “Land Change Modeler” extension available under IDRISI. The results showed seven (07) classes of occupation and land use. There were agglomerations, mosaics of fields and fallow land, water bodies, dense forests, gallery forests, swamp forests, and shrubby wooded savannahs. The observation of the vegetation cover over the period of 15 years from 1990 to 2005 showed a decrease from 71.55% to 63.42% in the surface area of the Ouémé Delta. A similar trend was noticed from 2005 to 2020 when it reached 55.19%, entailing a loss of 16.37% of the surface area of natural habitats in 30 years. The two drivers of such changes are the fertility of alluvial soils for agriculture along and urbanization. The predictive modeling developed for 2035 reveals a slight increase in the area of dense forests and shrubby wooded savannas, contrary to the lack of significant decrease in the area of gallery forests and swamp forests. This is key information that is expected to be useful to both policy and decision makers involved in the sustainable management and conservation of natural resources in the study area.

The importance of plants in the urban environment is sufficiently demonstrated by their potential and the ecosystem services they generate for the environment and populations. The present work aimed at assessing the contribution of avenue trees to carbon sequestration in the municipality of Sèmè-Podji in Benin. The methodological approach used has allowed making the inventory of trees along 26 kilometers of managed roadways. The diversity and structure parameters were computed to assess the floristic potential, the diameter and height structure of the trees, then the sequestered carbon from the allometric equations established for urban environments. The results revealed 19 species grouped into 12 families and 17 genus along the explored streets. Shannon's average diversity index (3.25±0.13 bits) and Pielou's equitability (0.76±0.04) explain the dominance of a few species, among which the most representative are Terminalia catappa (33.79%), Delonix regia (12.5%), and Khaya senegalensis (9.72%). The diameter and height structures are irregular, with average of 46.75 ± 33.46 cm and 10.35 ± 5.33 m respectively. The aerial biomass for the inventoried streets is 756.16 t/ha, corresponding to a carbon stock of 378.17 t/ha, that is the equivalent of 102.09 t of CO2 per hectare. It appeared from this study that the floristic procession and the structural characteristics of the avenue trees are limited to ensure the socio-ecological functions in the municipality of Sèmè-Podji. However, this information could encourage decision-makers to take reforestation measures to increase the vegetation cover of the streets and for better management of the city's urban forestry.

Background. Green spaces contribute to a significant life quality and maintain the sustainability of cities. In Benin, despite the political greening willingness, municipalities are experiencing technical issues in finding suitable spaces to achieve this goal. This study should serve many other towns. It aims at identifying suitable areas for green spaces to integrate landscaping into urban planning in Abomey-Calavi district. Methods. The multi-criteria analysis combining GIS and the hierarchical classification approach were performed. Six factors (land use, altitude, slope, distance from main roads, proximity to urban centres and distance from flood zones, water bodies) were combined using the ArcGIS "Spatial Analysis" extension to generate a map of green space suitability. Results. large areas of land, of which 23.27% are very suitable and 26.06% are suitable for landscaping in this municipality. The ranking of the factors revealed altitude, proximity to road networks, large conurbations and distance from wetlands accounting for 18%, compared with 14% for the other factors regarding the study environment. However, the use of these results must take into account the existing inhabited areas for a good site selection. Conclusion. These outputs guidance to decision-makers in choosing suitable sites for green spaces there and integrating them into sustainable development.