Abstract
Assessment and management of the environmental impacts of forest harvesting operations have become increasingly critical factors in practicing commercial forestry. This study investigated soil disturbance from a forest logging system operation on an 8-hectare mixed broadleaved stand in compartment no. 309 in Gorazbon district in Kheyrud educational and research forest. The objective of this study was to assess soil disturbance from ground-based skidding system operation contribute to statistically significant changes in bulk density and penetration resistance at various depths below the soil surface and changes in bulk density and penetration resistance related to different traffic intensities. A systematic predetermined grid that was laid out prior to harvesting to measure soil disturbance, and pre-and post soil disturbance were recorded by a visual assessment. Soil compaction and penetration resistance were measured by using a double sampling method consisting of a hammer driven hand corer and a hand-held soil penetrometer. Bulk density and soil strength measurements were taken at three depths: 10, 20 and 30 cm. Detrimental compaction was recorded for the soil bulk density results. Detrimental compaction was recorded for the soil penetrometer after medium and intense machine passes. Post-harvest detrimental soil disturbance wasn’t exceeded the USFS maximum allowable area that can be detrimentally impacted. Soil resistance results demonstrated no detrimental compaction in area to the skid trail center and wheel ruts.
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