Evaluation of anthropization indicators of the floristic landscapes of Kaélé hills in the Sudano-Sahelianzone of Cameroon

Abstract

This work focuses on the influence of anthropogenic activities on the phytodiversity of Kaélé hills, particularly those of Lara, Boboyo and Midjivin, in the Mayo-Kani Division, Far North Region of Cameroon. The aim is to assess the effects of the exploitation of the natural resources of these hills on the ligneous plants in order to contribute to their sustainable management. Two methods were used for this study: floristic inventories and ethnobotanical survey. The inventory design consisted of three blocks (hills) which are main treatments, the hillsides which are secondary treatments and the plots which are the replications. The species were inventoried in plots of 40 x 30 m each arranged from the bottom to the top of each hill on each of the two slopes and separated by 10 m of intervals (down-up and left-right). For the ethnobotanical survey, interviews were carried out with 385 people in order to assess the importance of the resources of these hills and the activities carried out there. 2495 woody individuals were inventoried, distributed in 35 species, 29 genera and 19 families over all the three hills. The main signs of disturbances recorded are marks of cutting, bark harvesting and pruning. The anthropization index is most noticeable on species on Lara hill such as Terminalia brownii (105 individuals), Grewia bicolor (88 individuals), Ficus abutilifolia (72 individuals). On Boboyo hill, the anthropization index is most noticeable on species such as Terminalia brownii (60 individuals), Grewia bicolor (73 individuals), Ficus abutilifolia (64 individuals), and on Midjivin hill, they are Terminalia brownii (74 individuals), Ficus abutilifolia (72 individuals) and Grewia bicolor (57 individuals). The species used in the local pharmacopoeia in order of appreciation by exploiters are: Terminalia brownii (19.9%), Azadirachta indica (17.97%), Anogeissus leiocarpus (16.14%) and Croton pseudopulchellus (13.76%). Eleven species are used in crafts, amongst which the most used are Terminalia brownii (93.77%) and Grewia bicolor (83.83%). This work has shown that the floristic diversity of the Kaélé hills is under anthropogenic pressure, thus leading to the disappearance of several plant species and the fragmentation of the natural habitat of biodiversity.