Floristic diversity of urban plant formations in southern Benin (West Africa)

Trees in urban areas have become an essential element for sustainable environment. However, in some African cities, the emphasis is often not placed on this forest heritage. The present study carried out in the districts of Abomey-Calavi, Allada and Cotonou in southern Benin aimed to assess the diversity of trees in public and private green spaces for the improvement of the urban environment. The method of itinerant surveys was used to identify the plant species found in the alignment trees, the green public squares and the concessions of these cities. During the study, the dendrometric and geographical parameters of trees with dbh ? 15 cm were collected. The diversity index, biological types and phytogeographic affinity of the species were analyzed. The results showed a floristic richness composed of 61 plant species distributed in 56 genus and 30 families. Leguminosae (33.3%), Arecaceae (16.0 %), Combretaceae (10.0%) are the dominant families. Shannon's diversity index and Pielou's equitability index are respectively between 2.92 to 3.03 bits and 0.65 to 0.67 bits. Mesophanerophytes are also abundant (57.0%). The relative abundance of pantropical species over other phytogeographic types confirms the loss of local biodiversity in our urban environments. The present study constitutes an important awareness for the preservation of green spaces in these cities.

Keywords: urban biodiversity, urban green space, biological types, phytogeographic types, Benin