عنوان مقاله [English]
Nowadays, the importance skid trails and in accordance with forest harvesting and silvicultural methods in the forestry sectors in the Hyrcanian forest, northern Iran, the necessity of the accurate and comprehensive assessment of these trails must be postulated. Forest machinery traffic on skid trails also has a large influence on the soil physical properties, so that, these properties cannot be restored after several years in skid trails. The aim of this study was to measure the runoff rate in two slopes classes of 0- 20 and 20-40 percent in the skid trails. For this purpose, the runoff was measured in the plot level in two area on the skid trails and control area in Gorazbon district in the Kheyrud Forest. In this study, due to more reps and get more useful data, the natural rainfall were used. According to the normality of runoff data, the compare mean was used between them by parametric tests. The results showed that skid trails and forest cover change in natural forests were the main cause of the increase in runoff, and also the type of coverage, change of seasons and the interactions between them had a significant effect on the runoff yield. In other words, the amount of rainfall and the change of seasons were the important factors affecting the runoff results. But, the trail slope and their interactions had no significant effect on the runoff.