Redalyc.Effects of Skidderon Soil Compaction, Forest Floor Removal and Rut Formation (original) (raw)
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Effects of Skidder on Soil Compaction, Forest Floor Removal and Rut Formation
An extensive field trial was set up to examine the influence of traffic intensity (5, 10, and 15 skidding cycles) (i.e. pass back and forth on the skid trail) and skid trail slope (0-10, 10-20, and > 20)% on soil compaction, forest floor removal, and rut depth after logging. The results showed that dry bulk density and rut depth increased with the increase of traffic frequency and slope, but floor coverage decreased. Within each traffic treatment soil compaction raised with the increase of skid trail slope, so that significant differences in dry bulk density were observed between slopes lower than 20% and those greater than 20%. Bulk density has become quite close to the critical value after 15 cycles. We observed soil rutting on the treatments started with 10 cycles. Soil disturbance increased significantly on slopes with less than 20% inclination with a dry bulk density of 1.157 g cm-3 after 5 cycles compared to 0.923 g cm-3 on slopes lower than 10%. In addition the litter mass on the treatments with 10 cycles and slopes greater than 20% (386.586 kg ha-1) was significantly lower (p < 0.05) than treatments with 15 cycles and slopes lower than 10% (545.382 kg ha-1). Data suggest that disturbance increased earlier in the steep treatments than in less sloping conditions. The dramatic increase of soil disturbance on treatments with slopes greater than 20% may be associated with increasing load on the rear axle combined with slipping on steep slope trail.
Effects of Skid Trail Slope and Ground Skidding on Soil Disturbance
The effects of traffic frequency and skid trail slope on dry bulk density, litter mass and rutting are examined. Treatments included a combination of four different traffic frequencies (3, 7, 14, and 20 passes of a rubber skidder) and three levels of slope (<10%, 10%-20% and > 20%.) The results showed that dry bulk density, rut depth and soil displacement increased with the increase of traffic frequency and slope, but floor coverage decreased. Within each traffic treatment soil compaction raised with the increase of skid trail slope, so that significant differences in dry bulk density were observed between slope of < 20% and those one >20%. Bulk density has become quite close to the critical value after 14 cycles. With increase of the skidder cycles from 14 to 20, bulk density remained approximately constant. We observed soil displacement on the treatments with 7 cycles: rutting on the treatments started with 7 cycles and slope of >20%. Soil disturbance increased significantly on slopes with > 20 % inclination with a dry bulk density of 1100 kg m-3 after 3 cycles compared to 830 kg m-3 on slopes < 10 %. In addition the forest floor mass on the treatments with 7 cycles and slopes of >20% (437.6 kg/ha) was significantly (p<0.05) lower than treatments with 14 cycles and slopes of <10% (841.4 kg/ha.) Data suggest that disturbance increased earlier in the steep treatments than in less sloping conditions. The dramatic increase of soil disturbance on treatments with slopes of >20% may be associated with increasing load on the rear axle combined with slipping on steep slope trail.
Effects of wheeled cable skidder on rut formation in skid traila case study in Hyrcanian forest
Journal of Forestry Research
The impact of skidding operations on forest soils can be divided into three major categories: soil profile disturbance, soil compaction, and soil puddling and rutting. The present study was designed as a factorial experiment in the Kheyrud Forest with a Timberjack cable skidder to evaluate the influences of number of machine passes and soil moisture of skid trails on rutting over a fine-grained soil, and to quantify these effects. The effects of soil moisture of 20%−30%, 30%−40% and 40%−50% and different levels of compaction were studied. Compaction treatments were applied using different numbers of skidding passes (1, 5, 10, 15, 20, 25, 30 times). Result shows that an increase in the number of machine passes could increase rut depth, but the majority of rutting was occurred after the initial few machine passes. Also rut depth at soil moisture of 40%−50% was higher than rut depths at soil moisture of 30%−40% and 20%−30%. The average rut depth in soil with 20%−30%, 30%−40% and 40%−50% moisture was 17, 22 and 35 cm, respectively. Rut depths were increased significantly with soil moisture and number of machine passes. It is suggested that skidding operations should be planned when soil conditions are dry in order to minimize rutting., but if skidding must be done under wet conditions, the operations should be stopped when machine traffic could create deep ruts.
Journal of Forest Science, 2010
In this study, the effects of slope and traffic intensity on soil compaction, rutting and forest floor removal was evaluated on a skid trail in the natural forest of north of Iran. Combination of two levels of slope < 20% (SC1) and > 20% (SC2) and three levels of traffic (one, five and nine traffics) were studied. Treatment plots, with three replications, were established on the skid trail prior to skidding. The results of this study showed that all bulk densities were considerably higher in SC2 than in SC1 and average soil bulk densities were measured from 1.07 (g∙cm–3) to 1.23 (g∙cm–3) on skid trail and 0.91 (g∙cm–3) in undisturbed areas. With the increment of traffic, soil compaction increased but there was no significant difference among the three levels of traffic frequency in SC1 whereas it was significant between one and five cycles in SC2. Greatest rut depth was measured as 12 cm at nine traffics in SC2, although increase of traffic density caused deeper rut depth at a...
Abstract -Key message Skidding operations significantly influenced soil physical properties up to a 2-m distance from the wheel ruts in a forest ecosystem. The most significant changes in soil properties were identified within a 0.5 m to 1 m transitional zone. -Aims The main purpose of this investigation was to determine how far into a forest stand changes in soil physical properties were evident due to skidding operations. & Methods Treatment plots with three replications included combinations of four distance zones at 0.5 m intervals (0 to 2 m in distance) on both sides of skid trail edges to the forest, three slope gradient levels were applied (gentle <10 %, moderate 10–20 %, steep >20 %) and two levels of traffic intensities 20 and 40 passes (with a rubber-tyred skidder, model HSM 904). A total of 576 soil samples were used in this study. -Results Results showed that the physical properties of soil were significantly changed by each traffic intensity in the first distance zone, where the slope was >20 % compared to soil changes at a slope of <20 %. The largest changes in soil properties were identified at 0.5 m transitional distance zones for a slope gradient >20 % after 20 and 40 skidding cycles. -Discussion Dry bulk density values reached its maximum levels in the first 0.5 m from the skid trail on slopes >20 % after 40 skidding cycles
2009
The use of skidding machinery in logging operations causes destructive effects especially on soil but has many advantages such as extracting long and heavy logs, optimum use of useful logging time and absence of defect in wood production quality and thus an increase in the added value of wood. In this research compartment 40 of the second district of Nav-Asalem in northern Iran at an altitude of 1,050-1,450 m above sea level was chosen in order to assess the amount of displaced soil volume and depth of ruts due to the traffic of Timber Jack 450C rubber wheeled skidder along the skid trail. Therefore, the correlations between two independent variables, longitudinal slope and soil texture, with two dependent variables, displaced soil volume and average depth of rut, along the skid trail were examined after 20 passes of skidder machinery. The results of this research showed a significant difference between the longitudinal slope increase of skid trail and the amount of soil volume displaced (P < 0.001). However, there was no significant correlation between the mean rut depth and different classification of longitudinal slope along the skid trail. The highest measured rut depth was 22 cm and occurred in the slope class of more than 25%. There was no significant correlation between the amount of displaced soil volume and rut depth with changes in soil texture along the skid trail.
Forests
Several studies investigated soil disturbances caused on skid trails by forest logging. However, there is still a lack of knowledge about the severity and the distance of disturbances along both sides from the trails. The aims of this study were: i) to investigate the changes in physical and chemical properties of soil along the sides of skidding trails; ii) to measure the effects of soil compaction on of maple seedlings growth. Two levels of trail gradient (< 20% and >20 %), four levels of traffic frequency (3, 8, 15, and 30 passes) and four distance buffer strip zones (0.5 m intervals from 0 to 2 m in distance) on both sides of skid trail edges were analyzed. Each treatment included three replicate plots. In order to investigate the effect of compaction on seedlings emergence and growth, maple seeds were sown after logging. The results highlighted significant changes in physical and chemical properties of soil for each traffic frequency in the closest buffer strip (from 0 to...
Effect of the skid trail cross section and horizontal alignment on forest soil physical properties
Journal of Forest Science, 2017
Horizontal alignment and cross section characteristics of a skid trail in a ground-based skidding system including curves, wheel ruts and cross slope can impact on the forest soil. In this study the measurement of cross section and vertical alignment of skid trail in Bahramnia forestry plan was done using a levelling instrument. Horizontal alignment of skid trail including straight routes and curves was taken using polar methods. A 3D map of skid trail was produced in AutoCAD Civil3D software. Soil bulk density was measured after sampling the soil with a core sampler. Results showed that in straight routes, soil bulk density increased by increasing the cross slope of skid trail. Moreover, soil porosity decreased with the increasing cross slope. There was a significant difference between cross slopes in soil moisture. On curves, maximum bulk density occurred when the cross slope was 10%. Findings about soil porosity and moisture on curves of skid trails were similar to those of strai...