Vegetation characteristics of bowé in Benin (West Africa)

Abstract

Bowé are particular form of degraded land where ferricrete, a hard erosion-resistant layer, is exposed. This study investigated vegetation characteristics of bowé (species composition, life form, chorological type, and plant family) in the semiarid and sub-humid climate zones in Benin. In both climate zones, bowé sites were characterized by grassland and savanna. The species composition on bowé varied according to the climate zone. Woody species were frequent on bowé in sub-humid (51% of the total species recorded) than in semiarid (44%). Geophytes, hemicryptophytes and phanerophytes were frequent on bowé in the sub-humid than in the semiarid climate zone. The difference between the two climate zones on the occurrence of therophytes on bowé was not significant. The frequency of chamaephytes was higher on bowé sites in the semiarid zone. Afro-tropical, Afro-Malgache, Pluri regional African and Pantropical chorological types were frequent on bowé than in woodlands in each climate zone while the opposite was found for Guineo-Congolian and Sudano-Zambesian chorotypes. Plant families such as Amaranthaceae, Zingiberaceae, Chrysobalanaceae, Connaraceae, Loganiaceae, Moraceae and Ochnaceae were only found on bowé in the sub-humid climate zone, while Convolvulaceae, Loganiaceae, Rhamnaceae, Araceae, Colchicaceae, Cucurbitaceae, Olacaceae, Pedaliaceae, maranthaceae, and Cyperaceae were only found on bowé in the semiarid zone.