The impacts of ground-based logging equipment on forest soil

Abstract

Soil properties can be affected by heavy equipment used for skidding but these impacts vary greatly with site conditions and operational practices. We assessed the effects of ground-based skidding on site disturbance and soil physical properties. We also tested the effects of skid trail slope and traffic frequency on soil compaction, total porosity, and moisture content. On average, about 30% of all harvested area was disturbed to varying levels. Intact forest floor (undisturbed) and light slash were the dominant surface conditions, covering an average of 68.9% of harvested area. Deep disturbed soils accounted for only just over 1.1% of observations. Results showed that dry bulk density, total porosity and moisture content were affected considerably on skid trails by traffic frequency and skid trail slope. Measurements of soil properties in the surface layer (0–10 cm) showed that bulk density is 57% higher and total porosity is 31% lower on the skid trail compared to the undisturbed area. Average moisture content has been measured as 35% on the skid trail versus 47% in the undisturbed area.