Middle-Term Сhanges in Topsoils Properties on Skidding Trails and Cutting Strips after Long-Gradual Cutting: a Case Study in the Boreal Forest of the North-East of Russia

Abstract

In this work, physical and chemical properties of the upper horizons of podzolic light loamy soil were investigated 21–23 years after forest cutting. This was after the first shift of long-term, gradual felling was carried out by tree-length logging in wintertime in mixed conifer stands of the Middle Taiga of the Arkhangelsk Region in Russia. The increased density of the forest litter composition was observed. This was especially the case on skidding trails. On the forest floor of skidding trails subjected to a greater stress caused by timber skidding, lower total porosity and aeration porosity was observed, in comparison with the cutting strip and natural forest. It was established that timber skidding during wintertime does not affect the density of podzolic horizon composition. An inverse pattern was observed here: the total porosity and the aeration porosity became higher and were close to the optimum values for plant growth (54.16–52.99% and 15.72–19.97%). In the podzolic horizon on skid roads, comparison to the natural forest showed a significant reduction of phosphorus mobile forms and an increase in the amount of absorbed bases, which is the result of grassy vegetation overgrowth and natural birch regeneration. On skidding trails and cutting strips, the organic matter content and total nitrogen significantly increased, which is related to a change of light intensity, the composition of living ground cover and vigorous decompositions of the organic horizon and woody residues. In cutting areas, a system mosaic of soil cover developed, which differed according to favourable conditions for tree species regeneration, compared to the control stands.