The influence of Urbanisation on Phytodiversity and some edaphic properties in urban and peri-urban riverine fresh water wetlands of Bamenda Municipality

Abstract

AimsIn urban areas, human activities result to the discharge of a variety of chemical substances to the environment, playing a substantial role in soil quality, plant species diversity and human security. In order to suggest appropriate management strategies that ensures soil quality, their sustainable utilization and human security in the midst of urbanization, this study assesses the relationship between macrophyte diversity and some soil characteristics of wetlands in Bamenda Municipality, Cameroon at different stages of urbanization. It examines (i) macrophyte diversity and soil characteristics of wetlands adjacent urban and peri-urban areas. MethodsPlant communities were sampled for species composition and relative abundance, using the Braun-banquet method. Species richness was evaluated using the Simpson’s diversity index. Twenty-one soil samples (0 - 25 cm depth) were also randomly collected within the wetlands and analyzed for their physico-chemical characteristics using standard methods. The hierarchical cluster analysis (HCA) was used to group the area under managing units. ResultsFrom the results, 50 macrophytes species distributed in 28 families were documented in the area. The species observed were mostly emergent herbaceous plants (grasses) with only few shrubs and trees. The Simpson indices of diversity were 0.94 and 0.96 for the urban and control sites, respectively. The soils were slightly acidic. Sand, pH-H2O, pH-KCl, Na were consistently least variable across the three sites. Two significant clusters representing a combination of urban and peri urban/rural were formed from the hierarchical dendrograms for classification of the chemical variables for the surface soils wetlands with associations to plants species. The Mann-Whitney U test, revealed a significant lower (P <0.05) concentration of the chemical constituents of the control site and the urban sites indicating contamination.ConclusionIntensification and extension of urbanisation is reducing the diversity of the wetlands of the Bamenda municipality warranting monitoring.