Suitability of Soil Erosion Models for the Evaluation of Bladed Skid Trail BMPs in the Southern Appalachians

Abstract

This project measured soil erosion rates from bladed skid trails in the mountains of Virginia following a timber harvest, and compared measured erosion to four erosion model predictions produced by Universal Soil Loss Equation-Forest (USLE-Forest), Revised Universal Soil Loss Equation, v.2 (RUSLE2), Water Erosion Prediction Project-Road (WEPP-Road) using default files, and WEPP-Road using modified files in order to assess the utility of the models for these conditions. Skid trails were segregated into six blocks where each block had similar trail slopes and soils. Each block contained four skid trail closure treatments: (1) bare soil (Control); (2) residual limbs and tops (Slash); (3) grass seed (Seed); and (4) fertilizer, seed, and straw mulch (Mulch). All treatments had waterbars, the minimum trail closure best management practice (BMP), to provide upslope and downslope borders of experimental units. Site cover characteristics on each experimental unit were collected quarterly as input parameters for erosion models. The suitability of soil erosion models were evaluated based upon statistical summaries, linear relationships with measured erosion rates, Nash-Sutcliffe Model Efficiency, and a nonparametric analysis. Treatments were measured to have erosion rates of 15.2 tonnes ha −1 year −1 (Control), 5.9 tonnes ha −1 year −1 (Seed), 1.1 tonnes ha −1 year −1 (Mulch), and 0.8 tonnes ha −1 year −1 (Slash). It was determined that WEPP-Road: Modified (p-value = 0.643) and USLE-Forest (p-value = 0.307) were the most suitable models given their accuracy; however USLE-Forest may be better for making management decisions given its practicality.

Soil Disturbance Effects from Tethered Forwarding on Steep Slopes in Brazilian Eucalyptus Plantations

“…However, predicted erosion rates were much higher for skid trails with slopes of 6-11 degrees and spur roads at 38.56 and 56.27 Mg/ha/year, respectively. Vinson et al found a predicted erosion rate of 24.1 Mg/ha/year using USLE-Forest on bladed skid trails with water bars in Virginia on average slopes of 9 degrees, while the actual sediment trap yield was 15.2 Mg/ha/year [94]. Wade et al found erosion rates of up to 137.7 Mg/ha/year resulting from skid trails in Virginia [42].…”

Best Management Practices Influence Modeled Erosion Rates at Forest Haul Road Stream Crossings in Virginia

“…WEPP generally performs poorer than the USLE unless interior files are substantially changed and parameterized to represent site‐specific data (Vinson et al. ). Both models tend to overestimate erosion rates as they increase beyond 11.2 Mg/ha/yr (Lang et al.…”

“…; Vinson et al. ). Climate files were created using the CLIGEN database from the nearest research station to each site.…”

Direct and Indirect Effects of Forest Harvesting on Sediment Yield in Forested Watersheds of the United States

“…In the Southeast, direct effects are affected by the legacy of agricultural land use (Rivenbark and Jackson 2004; Jefferson and Mcgee 2013; Lang et al 2015), geologic and hillslope factors (Rivenbark and Jackson 2004; Aust et al 2015; Vinson et al 2017a, b; Lang et al 2018), relatively high precipitation amount and intensity compared to the rest of the U.S. (Hershfield 1961; Beasley and Granillo 1988; Terrell et al 2011), and intensive management (Grace 2005). Flat areas of the Coastal Plain exhibit very little direct effects due to the combination of low slope (McBroom et al 2008; Terrell et al 2011) and rapid revegetation which helps to reduce the risk of erosion and direct effects soon after harvest (Beasley and Granillo 1988; Ensign and Mallin 2001).…”