Effects of deforestation on the soil nutrient status : a case of Mpanga Central Forest Reserve, Mpigi District

Abstract

Understanding nutrient status (quantity and quality) in forest soils is important for sustainable management of forest resources and maintaining forest ecosystem services. In this study, five soil nutrient indicators; soil organic matter (SOM), nitrogen (N), phosphorus (P), potassium (K) and pH were measured in two different sites; a virgin forest and cultivated farmland within a radius of 1-2kms away from the forest edge. 10 soil samples were extracted from the forest and 30 soil samples extracted from the cultivated farmland using purposive sampling method. Soil samples were collected every after a distance of about 200meters from each site. A social survey was undertaken, and questionnaires were given out to community dwellers to obtain answers on the causes of deforestation and effects of encroachment on community livelihoods at Mpanga Central Forest Reserve. Data analysis was run in Minitab. The results showed that deforestation and subsequent cultivation significantly decreased soil organic matter, nitrogen, phosphorus and potassium compared to the undisturbed forest soil. Firewood was the most important material obtained from the forest followed by water for domestic use, medicinal herbs, climate remediation and raw materials for the crafts industry. An increase in wind throws due to reduction of tree cover, migration of animal species and climate change have negatively impacted onto the local community. Central forest meetings are held time and time again to promote restoration of the degraded forest patches by concerned native people and reduce forest encroachment as well. Provision of alternative sources of income to the youth and enacting of forest reserve protection guidelines by the forest officers are conscious recommendations documented from the concerned parties. Deforestation and cultivation had negative impacts on the soil nutrient status. Measures to conserve soil organic matter and prevent erosion should be implemented to sustain soil fertility and productivity.