Effect of soil surface disturbance on overland flow, sediment yield, and nutrient loss in a hyrcanian deciduous forest stand in Iran

[Display omitted] •A hydrologic study was conducted in the Hyrcanian Forest in northern Iran.•The present work assessed effects of forest disturbance on hydrologic responses.•The negative effect of forest degradation was verified on runoff and soil erosion.•Forest disturbance markedly affected nutrient loss and organic matter depletion. Disturbance of forest watersheds has numerous effects on up and downstream environments, including erosion and reduction in productivity in disturbed areas, removal of nutrients, and deposition of pollutants on the land surface by runoff contamination of water resources. Little research has been conducted on forest ecosystems despite the environmental problems induced by nutrient transport. Therefore, the present study was conducted to quantitatively compare sediment yield, surface runoff, and nutrient and organic matter (OM) loss from undisturbed and disturbed forest areas during rain events in the Research and Educational Forest Watershed of Tarbiat Modares University in northern Iran. The study involved two treatments with three replications using 6-m2 plots. Results verified the significant effects of forest degradation (P