Soil compaction associated with cut-to-length and whole-tree harvesting of a coniferous forest

The degree and extent of soil compaction, which may reduce productivity of forest soils, is believed to vary by the type of harvesting system, and a field-based study was conducted to compare soil compaction from cut-to-length (CTL) and whole-tree (WT) harvesting operations. The CTL harvesting system used less area to transport logs to the landings than did the WT harvesting system (19%-20% vs. 24%-25%). At high soil moisture levels (25%-30%), both CTL and WT harvestings caused a significant increase of soil resistance to penetration (SRP) and bulk, density (BD) in the track compared with the undisturbed area (p < 0.05). In the center of trails, however, only WT harvesting resulted in a significant increase of SRP and BD compared with the undisturbed area (p < 0.05). Slash covered 69% of the forwarding trail area in the CTL harvesting units; 37% was covered by heavy slash (40 kg-m'"2) while 32% was covered by light slash (7.3 kg-m'"2). Heavy slash was more effective in reducing soil compaction in the CTL units (p < 0.05). Prediction models were developed that can be used, to estimate percent increases in SRP and. BD over undisturbed areas for both CTL and WT harvesting systems.