Soil Recovery from Track Construction and Harvesting Changes in Surface Infiltration, Erosion and Delivery Rates over Time

In the Eden Forest Management Area of southeastern New South Wales, Australia, temporal trends in soil recovery from forest harvesting practices were quantified. Soil recovery was assessed in terms of changes in surface soil compaction, infiltration, and erosion on highly disturbed snig tracks and less intensely disturbed general harvesting areas. The study sites ranged in age from 0.5 to 5 yr since disturbance. Maximum impact was noted to coincide with the period immediately after track construction and harvesting, and the effects decreased significantly over the following 5 yr. However, high values of bulk density in the 5-yr snig tracks revealed the persistence of the effects of machinery compaction. The degree of surface compaction and its recovery with time did not vary significantly with soil type, but erosion rates did, as the tendency for sediment transport processes on the more erodible granite sites to be dominated by rill flow affected not only sediment production rates, but also the recovery of these sites over time. The data indicated that cross banks were relatively ineffective in trapping fine-grained material.