SURFACE RUNOFF AND SOIL LOSS FROM A SKID TRAIL AND A LOGGING ROAD IN A TROPICAL FOREST

Abstract

Skid trails and logging roads have been identified as main sources of sediment in stream water of logged-over forests. Scientific information cm these problems is still lacking particularly in the tropical forest in Malaysia. Surface runoff and soil loss were measured using erosion plots from an undisturbed forest, a skid trail and a logging road. Results from a two-year study revealed that the average surface runoff from the undisturbed forest, skid trail and logging road were 62.9, 391.4 and 545.2 mm y^-1 respectively. The values were 2.3, 14.5 and 20.3% of the total rainfall. This surface runoff generated 453.7, 10 069.7 and 13 340.7 kg ha^-1 y^-1 of soil loss from the undisturbed forest, skid trail and logging road respectively in the first year after logging. In the second year, the losses decreased by 80% to 2111.3 kg ha^-1 y^-1 for the skid trail and by 77% to 3146.7 kg ha^-1 y^-1 for the logging road. Drastic reduction in the soil loss was probably due to a rapid recovery in soil stabilization arising from fast re-establishment of ground cover and emergence of seedlings on the logging road and skid trail.