Phytodiversité et services écosystémiques associés aux plantations d’alignement des rues aménagées de la ville de Grand-Popo au Bénin

Abstract

The importance of urban vegetation in generating ecosystem services in general has been widely demonstrated. In Benin, as well as the social and ecological benefits attributed to avenue trees, they also contribute significantly to the provision of supply and socio-cultural services via a range of uses by the population. This study assesses the contribution of plant biodiversity in city streets to the supply of goods and services to residents of Grand-Popo in Benin. The methodological approach used involved counting the number of trees planted along ten kilometres of managed roadways and conducting interviews with 164 households on the services provided by these trees. The diversity parameters were calculated to assess phytodiversity along these roadways. A table was complied to show the types of uses of tree organs in relation to existing ecosystem service categories. A total of 540 trees, belonging to 26 species and 17 families, were counted along the main streets of the city. Shannon's average biodiversity index (3.61 ± 0.14 bits) and the Pielou index of evenness (0,76 ± 0,06) show that some species are dominant, the most representative of these being Cocos nucifera with 20 % of total individuals. These avenue trees were mainly planted by the public authorities for shade, ornamental and carbon sequestration purposes. In practice, the uses made of these trees and the introduction of new species that are useful to the adjacent populations equate to the provision of more than nine ecosystem services, with shade and food rated as particularly important. To develop urban forestry, this kind of information would help to promote ecosystem services without compromising the viability of urban tree plantations.