Impact of Forest Road Construction on Topsoil Erosion and Hydro-Physical Soil Properties in a Semi-Arid Mountainous Ecosystem in Turkey

Abstract

This study aimed at pointing out the environmental importance of road construction in a semi-arid high mountainous area on soil erosion and some important soil properties throughout the forest road. In total 60 soil samples in both forest and open area were collected from topsoil (0-20 cm) of a cut slope, fill slope, and control points along with a forest road route. The soil properties were determined in the laboratory and the soil loss amounts were determined by way of an Allgemeine Boden Abtrags Gleichung (ABAG) simulation model.As a result, the road construction phase significantly changed (p<0.001) the soil erosion trend. Annual soil loss amounts (t/ha/yr.) determined cut slope > fill slope > control in both forest and open areas. Consequently, road construction efforts significantly affected topsoil loss and some soil properties such as organic matter, available water-holding capacity, and bulk density. According to the created scenario, under the same slope (68.72%) and slope length (3.26 m) conditions, the highest soil loss trend was in cut slope, which was significantly different (p<0.001) from fill slope and control in forested and open areas.

The Effects of Using Wood Chips and Slash in Reducing Sheet Erosion on Forest Road Slopes

“…The values obtained in the present study were lower than those in other studies. In some studies, when the amount of sediment loss in cutslopes and fillslopes was compared, more losses were found in the cutslopes [6,10,36]. However, one study reported that 60% of the sediments from roads are caused by fillslopes, 25% by the road surface and 15% by cutslopes [12].…”

“…Usually, the main reason for increased erosion after the construction of forest roads can be listed as the elimination, in part or as a whole, of the protective flora along the way [5][6][7]. In addition, with increased cutslope length there is also an increasing rate of soil loss [8][9][10]. Moreover, possible causes of the accelerated erosion, which may take place following road construction on forested lands, include destruction or impairment of the natural soil structure and fertility, increased slope gradients created by the construction of cutslopes and fillslopes, decreased infiltration rates on parts of the road, interception of subsurface flow by the road cut gradient, decreased shear strength, increased shear stress, cutslopes and/or fillslopes, and concentration of generated and intercepted water [2,5].…”

The Effect of Using Chip and Slash in Reducing Sheet Erosion on Forest Road Slopes

“…The values obtained in the present study were lower than those in other studies. In some studies, when the amount of sediment loss in cutslopes and fillslopes was compared, more losses were found in the cut slopes [30][31][32]12]. However, it has been reported that 60% of the sediments from roads are caused by fillslopes, 25% by the road surface and 15% by cutslopes.…”

“…Usually the main reason for increased erosion after the construction of forest roads can be listed as the elimination, in part or in whole, of the protective flora along the way [7][8][9]. In addition, with increased cutslope length there is also an increasing rate of soil loss [10][11][12]. Moreover, possible causes of the accelerated erosion which may take place following road construction on forested lands include destruction or impairment of the natural soil structure and fertility, increased slope gradients created by construction of cutslopes and fillslopes , decreased infiltration rates on parts of the road, interception of subsurface flow by the road cut slope, decreased shear strength, increased shear stress, cutslopes and/or fillslopes, and concentration of generated and intercepted water [4,7].…”

Influence of Improving Materials of Forest Roads on the Surrounding Environment

“…The different erosive processes, either natural or caused by human activity, cause different materials to be moved and deposited in other areas where they did not exist before [2]. Human activities accelerate the process of erosion [3] and export of sediments through which they convert the soil into a non-renewable resource.…”