Effects of timber extraction on soil physical properties and organic carbon recovery during seven years after trafficking in Gorazbon District in Kheyrud Forest

Assessment and management of environmental impacts imposed by forest harvesting activities are one of the key factors that are increasing important. The purpose of this study was to investigate the effect of ground-based system on soil physical and chemical properties and the recovery process of these properties over the course of seven years. Hence, the compartments no. 316, 318, 310, and 309 of the Gorazbon District in the Kheyrud educational and research forest were selected. In this study, a completely randomized factorial design was applied and the treatments included duration (years) from timber extraction (one, two, five, and seven years), three traffic intensities (low, medium, and high) and soil depths (0-10 and 10-20 cm). The soil bulk density after seven years has not yet returned to the original state. There is still a significant difference between the control area and the skid trail. The amount of organic matter after seven years showed a recovery process compared with the first year after timber extraction, so that in the seventh year no significant difference was observed between the amount of organic matter in the control area and timber extraction track, while the amount of organic matter in the first year of timber extraction track is much lower than that of adjacent control areas. The recovery of some soil properties such as organic matter occurs faster than other ones like bulk density and porosity.