Floristic Diversity and Characterization of Peri-Urban Agriculture in Some Drains of the City of Douala (Cameroon)

Abstract

This study is situated within the context of rapid urbanization and the management of stormwater drains in Douala, aiming to assess the floristic diversity and agricultural practices in these disturbed environments, which play a key role in food security and ecological resilience for urban communities. The study involved an inventory of plants around five drains in Douala, conducted through floristic surveys. Species were identified and their abundance estimated, and floristic diversity was analyzed using the Shannon-Weaver and Pielou ecological indices. Similarity between sites was evaluated with the Sorensen index and a principal component analysis, with a particular focus on edible plants and local agricultural practices. A total of 67 species belonging to 24 families were recorded, with a marked dominance of Poaceae and pioneer genera such as Paspalum, Ipomoea, and Cyperus. Floristic diversity, measured by the Shannon-Weaver index (H'= 0.99) and low evenness (E = 0.23), indicates an unbalanced plant community dominated by a few cultivated and ruderal species. Additionally, 24 edible species mainly from the Solanaceae and Poaceae families were identified, highlighting the role of drains as urban agricultural spaces contributing to local food security. The floristic similarity analysis revealed significant homogenization between the Tongo Bassa and Kondi drains, suggesting common agricultural practices and environmental pressures. These results emphasize the need for integrated management aimed at diversifying crops and regulating agriculture in these polluted environments to preserve biodiversity, strengthen ecological resilience, and ensure food security for the neighboring populations.