Changes of key soil parameters five years after forest harvesting suggest slow regeneration of disturbed soil

Forest soil is susceptible to changes in its top layers. These changes occur during ground-based forest harvesting and the rate of soil regeneration depends on the environmental conditions and the extent of the disturbance. This paper was focused on analyzing the changes of soil characteristics such as the depth of the erosion profile, bulk density of soil, its penetration resistance, and the subsurface concentration of CO2 in soils five years after forest harvesting. The study took place in four forest stands harvested by a skidder and a harvester/forwarder combination. Statistic& analyses did not prove significant changes of the characteristics of the disturbed soil after the five-year period without machine traffic: the profile depth did not change significantly, except for one stand, where the ruts became deeper. Other characteristics, such as the bulk density of soil also did not show any significant regeneration (1.29-1.36 g cm(-3) in the rut; initial measurements versus 1.34-1.38 g cm(-3) in the rut; repeated measurements). The penetration resistance, as well as the subsurface CO2 concentration, were variable, and the results inconclusive. Our results suggest that five years was not enough time for soil to regenerate significantly after being disturbed by ground-based machinery.