The study was undertaken to assess the chemical changes in soil at a clear cutting of Scots pine (Pinus sylvestris L.) stand on Arenosol in South-Western Lithuania. The study determined the changes of organic carbon and plant nutrients in mineral topsoil and soil solution between and under skid trails, composed of logging residues, during the first 4 years after clear cutting.
The obtained data showed that, in general, significantly higher mean concentrations of NO3-N + NO2-N and NH4-N and, to a lesser extent, K2O and P2O5 were found under than between skid trails. However, higher concentrations of total organic carbon (TOC) were found up to 10 cm depth of mineral soil between skid trails. After 3 years mean concentration of NO3-N + NO2-N significantly increased only in 0-10 cm depth of mineral soil between skid trails but decreased up to the depth of 40 cm under skid trails. Mean concentrations of TOC increased between and, especially, under skid trails. Mean-while, the mean concentration of P2O5 decreased under skid trails and the concentration of K2O, both between and under skid trails, in mineral topsoil up to 10–20 cm depth.
In soil solution of fresh clear cutting, mean concentrations of NH4-N, NO3-N + NO2-N, total N (TN), K+, Ca2+ and Mg2+ significantly increased under than between skid trails and decreased in the 4-year-old clear cutting both between and under skid trails. However, in fresh clear cutting, mean concentration of DOC did not differ between and under skid trails but increased under skid trails in the 4-year-old clear cutting. There, mean concentrations of TN, K+, Ca2+ and Mg2+ were also significantly higher under skid trails.
Keywords: clear cutting, skid trails, mineral topsoil, soil solution, organic carbon, plant nutrients.