Impact of Eucalyptus camaldulensis plantation on an alluvial soil in south eastern Botswana
International Journal of Environmental Studies
Department of Geography, University of Ibadan, Ibadan, Nigeria; Department of Environmental Science, University of Botswana, Private Bag 0022, Gaborone, Botswana
This paper examines the impact of a 33-year plantation of Eucalyptus camaldulensis on an alluvial soil in Gaborone, south eastern Botswana, by comparing the soil under the plantation with similar soil under an adjoining native savanna woodland dominated by Acacia karoo. Soil clay content was significantly higher in the plantation soil in both the 0-10cm and 10-20cm layers. There were no significant differences between soil under the two ecosystems with respect to the levels of organic matter, exchangeable potassium and available phosphorus. Despite the higher clay contents of the plantation soil, exchangeable calcium and magnesium and pH were higher in soil under the native woodland. This suggests that E. camaldulensis immobilizes soil nutrients faster and that plantation nutrient cycles are less efficient than in the native Acacia woodland. Consequently, soil nutrient deficiency will limit plantation productivity after the first few rotations. It is important to adopt tree harvesting techniques that reduce drain on soil nutrients at the end of a plantation rotation. © 2005 Taylor & Francis Group Ltd.
Clay; Ecosystems; Hardwoods; Harvesting; Phosphorus; Alluvial soil; Organic matters; Soil nutrient; Woodlands; Soils; Clay; Ecosystems; Eucalyptus; Harvesting; Phosphorus; Soil; Acacia; Eucalyptus camaldulensis