Insufficient Logging Intervals Impede Upper Soil Recovery in Temperate Beech Forests: Insights From Two Case-Studies in Poland

Little is known about how forest operations affect the biodiversity of soil microarthropods and the litter decomposition rate in temperate beech forests. This study aims to ascertain this information. Two study areas were selected, each consisting of a chronosequence of three cutting blocks: one that had not been harvested in the previous 20 years, one harvested in 2017 and one harvested in 2021. In 2022, we examined skid trails in the harvested parcels, categorised as disturbed soil and soil that has not been impacted by any machine passage, categorised as undisturbed soil. There were five experimental treatments in total within each study area, including the control. For every treatment, we evaluated upper soil compaction, organic matter content and soil microarthropod biodiversity, which was measured using the QBS-ar index. To compare the variations in litter decomposition rates among treatments, we also set up a litter decomposition experiment based on the teabag method. Aside from the litter decomposition rate, which remained unaffected in all experimental treatments, we identified significant disturbances in the soil impacted by the machine's passage. Our results suggest that the recovery process for all variables studied was still incomplete after 5 years. Skid trail sites established 5 years ago continued to display values that differed from those in undisturbed and control areas. We recommend increasing the time interval between two consecutive logging operations in the same cutting block or implementing best management practices that can reduce the initial disturbance in the skid trails.