The effects of using soil protective mats of varying compositions and amounts on the intensity of soil disturbances caused by machine traffic

Abstract

ABSTRACTWe quantified the effectiveness of different soil protective mat compositions (brush, sawdust, combination of brush and sawdust) and densities (light density of 10 kg m−2 and heavy density of 20 kg m−2) on compaction and rutting on skid trails in mountainous forests following one, four, and 10 machine passes on two trail gradient classes (≤ 20% and > 20%). Soil bulk density and rut depth increased markedly with traffic frequency on both slope gradient classes on bare and protected soil, but soil protective mats delayed the onset of adverse soil responses and reduced the level of soil damage. Brush mats provided a more effective protection than sawdust and the combination of brush and sawdust and heavy density brush mats more so than light density mats. Compared to bare soil, heavy brush reinforcement significantly reduced bulk density for up to 10 passes on trail gradients ≤ 20% and four passes on gradients > 20%, regardless of soil protective mat composition. Light and heavy brush mats significantly reduced rut depth at all traffic frequencies on both slope classes. Because the effectiveness of soil protection afforded by the mats diminished with increasing traffic, brush mats provide a particularly effective protection for less trafficked trail segments where brush mats substantially diminished or even eliminated rutting altogether.