Biomass and ecosystem services valuation in support of urban climate-resilience in Dakar, Senegal

Rapid urbanization is a growing global concern that challenges sustainability in cities. Urban trees provide several ecosystem services, such as climate regulation, carbon sequestration, and air-pollution removal. The
sustainable benefits of these services imply the preservation of urban forests in developing countries, where trees are frequently removed and replaced by buildings and other infrastructure. Supporting informed decisionmaking requires accurate estimation and valuation of tree biomass and ecosystem services beyond conventional forest-based allometric approaches. This study used a scientific ecosystem services modeling tool to improve the accuracy of biomass estimates for the Mbao Protected Forest in Dakar. It uses the vegetation index (NDVI) as a proxy for historical biomass estimation (1988–2018) on the Google Earth Engine platform and the iTree Eco tool to estimate ecosystem services. Our analysis reveals that biomass decreased from 1.5 T ha⁻¹ in 1988 to 0.8 T ha⁻¹ in 2018. In the meantime, the Mbao forest sequestered approximately 1506.43 metric tons of carbon per year, valued at Francs CFA (CFAF) 15,547.8 thousand ($244,654.60). The total carbon stored amounts to 7892.17 metric tons, equivalent to CFAF 813.91 million ($128,073,957.51). For air pollution control, the model estimates that 44.83 t of O₃, NO₂, SO₂, CO, and PM2.5 were removed each year, corresponding to a value of CFAF 188,173.91 thousand ($29,610,371.36). The findings demonstrate that urban protected areas are essential for creating habitable, environmentally resilient cities that balance development with ecological health and quality of life. The study emphasizes the importance of integrating green infrastructure into urban policy planning to inform decision-making, particularly in rapidly urbanizing cities, and to achieve Sustainable Development Goal 11 (SDG 11).