Soil recovery from track construction and harvesting changes in surface infiltration, erosion and delivery rates with time

Abstract

The effects of timber harvesting activities are often characterised by significant changes in surface soil properties, runoff production and erosion rates. Here we quantify trends in surface soil recovery following timber harvesting activities, specifically snig track (skid trail) construction and logging, based on changes in soil surface compaction, infiltration, and erosion with time since initial disturbance. Sites range in age from 0.5 to 5 years. Surface erosion on the snig tracks and general harvesting areas (GHA), and sediment storage and delivery between the two areas, are measured using a large rainfall simulator. Surface soil compaction shows no significant recovery over this time period, illustrating the persistent effects of machinery compaction on surface soil structure. In contrast, surface infiltration rates on the snig tracks increase by a factor of two and snig track erosion rates decline by almost one-order of magnitude over the 5-year period. These findings have important implications for assessing the cumulative impact of timber harvesting activities.