Diversity and abundance of macrophytes of streams under different anthropogenic influences in the Buea municipality, southwestern Cameroon

Abstract

Macrophytes can occur as submerged, floating or emergent. They provide not only important structural supports in streams and river habitats, but also absorb and sequester pollutants, provide primary food production, nutrients and habitats to a wide range of macro and micro-organisms living in and around lotic sites. Their existence is however threatened by both anthropogenic and natural stresses. This study aimed to document macrophyte diversity and abundance in streams under different anthropogenic influences in Buea, southwestern Cameroon. Floristic surveys were carried out using 500 m long transects laid along the different streams. Plants encountered were identified and confirmed at the Limbe Botanic Garden Herbarium. One hundred and ten species belonging to 38 families and 83 genera were recorded. There were no floating species and only one stream had submerged species (Vallisneria spiralis L and Crinum calamistratum Bogner & Heine). The highest number of families (26), genera (58) and species (70) were obtained in Ndongo while the least of these taxa were obtained in Bulu (16, 35 and 39, respectively). Overall, Asteraceae and Poaceae were the most abundant, suggesting anemophilic dispersals. However, individual species abundances varied with streams. The highest diversity index (0.945) was in Wongangjio while the least (0.760) was in Nange, suggesting that waste discharge from car wash might influence species diversity negatively. The macrophyte composition was made up of obligate and non-obligate species as a consequence of anthropogenic influences. These results constitute baseline data for the area that can be exploited for further research and monitoring.