Assessment of the biodiversity of sacred forests in the Atlantic department in Southern Benin

In Benin, the sacred forests constitute vestiges of heavily anthropized primary forests. In order to assess the importance of plant biodiversity in the sacred forests of the Atlantic department in South Benin, a forest inventory was carried out in five islands of sacred forests (Hêkpazoun : 25 ha ; Avogbézoun, Sindomè, Ahouansêzoun et Assanmeyzoun : 10 ha each). Structural parameters were compared between forests with analysis of variance tests. The results obtained show that the specific richness of the woody plants varies from 6 species (sacred forest of Hêkpazoun) to 20 species (sacred forest of Avogbézoun) with good distribution of trees between the different species regardless of the sacred forest considered (diversity index of Shannon varying between 3.17 and 4.11). Regarding the dendrometric parameters, only the mean diameter varied significantly (Prob. <0.05) from one sacred forest to another. The largest trees were observed in the sacred forests of Avogbézoun (60.75 cm) and Ahouansêzoun (58.96 cm) while the smaller trees were observed in the sacred forests of Assanmeyzoun (32.03 cm) and Sindomè (42.50 cm). C. mildbraedii, F. thonningii, T. prieurianna, D. guineense, V. doniana and T. scleroxylon were the main characteristic species of sacred forests. Although the structural features do not indicate an alarming degradation of these ecosystems, measures must be taken for their conservation.