Minimizing soil impacts from forest operations
Several studies were conducted by Forest Service researchers and University and Industrial collaborators that investigated the potential for lessening soil surface disturbances and compaction in forest operations through modifications of machine components or harvest systems. Specific machine modifications included change in tire size, use of dual tire systems, reduction of tire inflation pressures, reductions in load size and ground pressure. Soil surface disturbances were most evident in sites with high soil moisture content that were lessened by lowering tire inflation pressures or using a dual tire configuration. Traffic intensity increased rutting potential of harvest sites, especially with the use of narrow tires. Traffic intensities varied spatially and in intensity in clear cut harvest operations with intensities that ranged between none to 100 or more. Soil physical properties responded to choice of tire size and inflation pressure with narrower tires and/or higher inflation pressures associated with increased soil compaction. Soil disturbance data collected in three clear cut operations in Alabama indicated no differences among the operations by location, but soil response varied depending on site properties. Soil physical properties did not necessarily reflect the intensity of soil disturbance.