Abstract

This study evaluates the effects of ground-skidding operations on the physical and chemical properties of soil at different levels of slope gradient and traffic frequency. Three levels of traffic (four, eight and 16 passes of a rubber tired slddder Timberjack 450 C), and two levels of slope gradients (gentle <20%, and steep >= 20%) were applied in three replicates consequently, 18 plots with 10 m long by 4 m wide were utilized in the study. In each sampling plot, three lines were set up perpendicular to the skidding direction. At three different points on each line (left track, between track and right track) one sample was taken from forest floor and the 0-10 cm soil layer. Soil bulk density, forest floor biomass, organic carbon (OC), nitrogen (N), phosphorus (P), potassium (K) and soil acidity (pH) were affected by traffic frequency and slope gradient. The soil class of our study area in soil classification according to WRB was Combisols. Soil texture was analyzed using the Bouyoucos hydrometer method and was determined to be clay loam along the trails. Soil bulk density was 60% higher in samples taken from skid trails compared with samples taken from an undisturbed area. The average forest floor biomass ranged from 2185 kg ha(-1) to 243 kg ha(-1) on the skid trails, while the respective value was 3335 kg ha(-1) for the undisturbed area. Skidding caused a decrease in the amount of soil OC (by 38%) and the concentrations of N (57%), P (25%), K (31%) and hydrogen ions (33%) compared with undisturbed areas. Increased soil disturbance occurred more markedly with fewer passes on the steeper trail. The dramatic increase in soil disturbance on the skid trail with a slope >20% is presumably associated with the difficulties of skidding on steep terrain. To minimize soil disturbance, skidding should be confined to areas with more gentle slopes and alternative harvesting methods should be used where slope gradients exceed 20%. We hypothesized that skidding can jeopardize the sustainability of forest ecosystems by creating unfavorable changes in soil characteristics and nutrient status. (C) 2015 Elsevier B.V. All rights reserved.

Keywords

Compaction; Ground-based operation; Litter mass; Logging

Published in

Geoderma
2016, Volume: 265, pages: 12-18
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Ilstedt, Ulrik

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG15 Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss


UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1016/j.geoderma.2015.11.009

Permanent link to this page (URI)

https://res.slu.se/id/publ/70137