This work is based on a review and the authors' experience from several case studies. It summarizes the main environmental impacts of radiata pine and eucalyptus plantation projects on the physical environment, and proposes some guidelines for mitigation. Site preparation for plantation, road construction, and ground-based logging (including log skidding and machinery displacements) are the operations that cause the major impacts on the physical environment. The main impacts on soil are

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... on, displacement, erosion by water, and nutrient depletion. Major impacts on hydrology are disturbances in the hydrologic balance as a consequence of changes in interception, evapotranspiration and surfface runoff, and physico-chemical water quality. Mitigation guidelines according to the fragility of the regional terrain are oriented toward comprehensive planning and the use of more appropriate establishment and harvesting techniques.