The impact of illegal farming on biodiversity of Sui river forest reserve in Sefwi Wiawso forest District, Ghana
Despite substantial loss of natural forest in Sui River Forest Reserve by human disturbances, mainly illegal farming, little is known about the impact of the disturbances on biodiversity status of the forest reserve. To investigate the impact of illegal farming on biodiversity of Sui River Forest Reserve, flora and fauna were sampled in three forest compartments (163, 106 and 171) within the reserve. Compartment 163 was heterogeneous having two forest types, undisturbed forest (UF) and disturbed forest (DF) whilst compartments 106 and 171 were homogeneous. Compartments 106 was undisturbed forest and 171 was disturbed forest. The undisturbed forests (UF) served as control plots. In each forest block within the compartments, two 25m x 25m plots were randomly demarcated and these were subdivided into twenty-five 5m x 5m subplots. Fifteen (15) of the subplots accounting for 60% of the plot area were randomly sampled for tree species, regeneration of tree seedlings, herbs and fauna. Species diversity was determined using Shannon-Wiener Diversity Index (H1). Species richness for flora and fauna in the undisturbed Forest (UF) was quantitatively higher than in the disturbed Forest (DF). Celtis mildbraedii was identified as the dominant and an indicator species for the undisturbed forest whilst Musanga cecropioides and Trema orientalis were identified as dominant and indicator species for the disturbed forest. Illegal farming had a direct impact on the regenerative capacity of the reserve resulting in colonisation by an invasive species Chromolaena odorata which displaced native species resulting in poor regeneration in the disturbed areas. The widespread loss and fragmentation of the original closed canopy of the moist semi-deciduous forest and the destruction of suitable habitat niches through the removal of forest vegetation in illegally farmed areas resulted in low fauna species and low diversity in the disturbed forest. The findings of the study revealed that illegal farming has negatively impacted on the biodiversity in Sui River Forest Reserve. Thus sustainable forest management is required to reduce the forest degradation process and biodiversity loss.
A Thesis Submitted To the Department of Theoretical and Applied Biology, College Of Science, Kwame Nkrumah University of Science And Technology – Kumasi, in partial fulfilment of the Requirements for the Award of Master of Science in Environmental Science, 2013