Aidin Parsakhoo;Majid Lotfalian;Ataollah Kavian;Seyed Ataollah Hossein

Department of Watershed Management, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University, Sari, Iran;Department of Forestry, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University, Sari, Iran;Department of Forestry, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University, Sari, Ira;Department of Forestry, Faculty of Forest Sciences, Gorgan Agricultural Sciences and Natural Resources University, Golestan Province, Gorgan, Iran

road prism;soil erodibility;aggregate stability;wet sieving;Lat Talar forest;SIMULATED RAINFALL;EROSION;RUNOFF;WATER;LANDSLIDE;RATES;ARE

We measured erodibility and mean weight diameter (MWD) of soil aggregates in different parts of a forest road. Samples of topsoil were collected from cutslope, fillslope, road surface and forest ground to assess the texture, bulk density, moisture, CaCO3 and organic matter. Soil aggregate stability was determined by wet sieving. Soil erodibility on the road surface was 2.3 and 1.3 times higher than on the fillslope and cutslope, respectively. The forest soil had the lowest erodibility. Aggregate stability of cutslope and road surface were low and very low, respectively. There was a significant negative relationship between cutslope erodibility with CaCO3 and sand content. Cutslope erodibility increased with increasing silt, clay and moisture content. On fillslopes, MWD increased with increasing rock fragment cover, plant cover, litter cover, organic matter and sand. There was a strong negative correlation between fillslope erodibility and organic matter, sand and MWD. There was no significant difference between erodibility of bare soil and soils beneath Rubus hyrcanus L. and Philonotis marchica (Hedw.) Brid.