Diversity of the epiphytic flora of the urban ecosystem of Douala (Cameroon)

Urbanization is one of the real factors of irreversible degradation of tropical ecosystems in the world in general, and in Cameroon particularly, having thus a consequence on the biodiversity. The aim of this study is to identify the epiphytic flora of an urban ecosystem. The work took place in the city of Douala, littoral region of Cameroon. The surveys made in seven quarters located in industrial, port, urban and peri-urban zones, in 40 parcels of 400 m² (20 m x 20 m). On each tree prospected, epiphytes were found and identified on site or with the reference manuals, or in the National Herbarium of Cameroon. A total 26 species of phorophytes were identified in the studied area, Elaeis guineensis and Mangifera indica were the most colonized trees with 55 and 27 epiphyte species. For the epiphytes, 80 species were identified, grouping 60 genera into 30 families. The family of Asteraceae was predominant with 5 species. Microgramma sp and Nephrolepis biserrata were most encountered on the phorophytes with the occurrences respectively of 66.21 % and 26.55 % of the phorophytes. The site showed a low Shannon-Weaver index with a value of 2.89 bits, and a Pielou index of 4.92. Accidental epiphytes had the higher number of species (53 species), followed by semi-epiphytes, and the strict epiphytes showed the lowest number of species (8 species). The epiphytes are present in urban ecosystem, and should be manage to preserve biodiversity of rain forests.
Key words: Biodiversity, Coastal region, Epiphytes, Phorophytes, Urbanization.