THE EFFECTS ON SOIL COMPACTION OF TIMBER SKIddING By TRACTOR ON SKId ROAd IN PLANTATION FOREST IN NORTHERN TURKEy uTjecaj prIvlačenja drva TrakTOrOm na ZbIjanje tLA NA tRAKtORSKIM VLAKAMA I PUtEVIMA U planTaŽnIm Šumama sjeverne Turske

In this study, degree of soil compaction and rutting caused on the skid road by rubber-tired tractor was investigated in northern pine plantation forest in Turkey. In research area, the cross sections were selected in every 20 meter along the skid road. Penetrometer measurements were made in each cross section. Also, the soil samples were collected to on the skid road and forest site. The rutting was measured in each cross section. The results of in this study, on the skid road had shown changes of soil depth and soil compaction during skidding operations. The major soil compaction was also more occurred in the first four passes. The rutting has been less by increasing the number of passes on the skid road. Rut depth became significant after 4th, 8th, 12th, 16th and 20th passes, reaching an average 2.6, 3.5, 4.1, 4.6 and 4.9 cm, respectively. The values penetrometer were found on skid road for every cross section (5 different points) and also, on forest soil at edge of skid road (1 point). The soil compaction values were evaluated due to penetrometer measurements.