Assessing the Impact of Forest Machinery Passage on Soil CO2 Concentration

Forestry machinery plays a key role in forest management, but its increasing weight significantly impacts soil condition. Machinery passage causes soil compaction, which alters the physical, chemical, and biological properties of the soil and affects CO2 concentration. This study aimed to measure the impact of soil compaction on the evolution of CO2 concentrations over three years. Research was conducted near Zvolen, Slovakia, where soil was compacted in 2020 by a forestry skidder. The intensity of compaction was evaluated using a digital penetrometer. CO2 concentrations were measured with a Vaisala MI70 device, with 22 measurements taken post-compaction at an average interval of 52 days. Soil compaction was characterized by a derived penetration index. At a depth of 10 cm, the average penetration index was 119%, indicating a 19% increase in resistance. The highest index, 134%, was found at a depth of 3 cm. A correlation of 0.4 was found between the number of passes and CO2 concentration at 30 cm depth, and 0.8 between penetration index and CO2 concentration. Results showed a significant impact of forestry machinery on soil CO2 concentration, even three years later. Therefore, operating practices should minimize machinery impact on forest soils.