Urban Flora Structure and Carbon Storage Potential of Woody Trees in Different Land Use Units of Cotonou (West Africa)

Abstract

Urbanization is a current concern, particularly in Africa, where it is expected to continue and increasingly threaten the effectiveness of plant biodiversity, natural carbon sinks, and the sustainability of cities. This paper investigates the structural parameters and carbon storage potential of trees in the land use units of the city of Cotonou in southern Benin. A total of 149 plots at 2500 m2 each were randomly generated, and trees with a diameter ≥ 10 cm were inventoried. ANOVA revealed that the means of structural parameters (diameter and height classes) and carbon stock rate varied significantly (p < 0.001) across land use units in the city. Tree basal area is estimated at 4.52 ± 5.24 m2 ha−1, with an average of 12.72 (13) feet ha−1. The average diameter of the trees is estimated at 57.94 ± 29.71 cm. Approximately 1000 kg ha−1 (0.94 × 103 kg ha−1) of carbon is stored in the city of Cotonou. Green spaces (1.21 × 103 kg ha−1) and roads (1.19 × 103 kg ha−1) are the units that recorded the highest carbon stocks. Khaya senegalensis, Mangifera indica, and Terminalia mentally lead the top ten species with high stock potential. This study demonstrates the contribution of urban trees to global atmospheric carbon reduction, which varies by species, land use units, and tree density. Future research could investigate an i-Tree Landscape approach for urban carbon estimation. This could reinforce urban carbon data availability for urban ecological planning.