Best Management Practices, Estimated Erosion, Residual Woody Debris, and Ground Cover Characteristics Following Biomass and Conventional Clearcut Harvests in Virginia’s Mountains

Abstract

Water quality best management practices (BMPs) developed for conventional forest harvests may be adequate for biomass harvests, yet quantitative data is lacking. This study compared estimated erosion, operational feature areas, BMP implementation rates, ground cover characteristics, and downed woody debris quantities following biomass and conventional harvests in the mountains of Virginia. Haul roads on biomass harvests had significantly higher estimated erosion rates (P = 0.064) and masses (P = 0.045) than conventional harvests, but conventional harvests had higher erosion contributions from skid trails (P = 0.089) and averaged more estimated erosion mass overall, despite being significantly smaller in size (P = 0.054). There was significantly less area in heavy slash (P = 0.076) and lower estimated mass of residual downed woody debris (P = 0.001) on biomass sites than conventional sites (10.98 and 27.95 tons/ac, respectively). Site-wide BMP implementation scores (P = 0.041), streamside management zones (SMZs) (P = 0.024), and skidding (P = 0.063) were significantly higher on biomass sites than conventional sites. BMP implementation scores were significant predictors of estimated erosion rates (P < 0.001, R2 = 59%), indicating that adequate levels of existing water quality BMPs are effective for erosion control on both conventional and biomass harvests.

A Comparison of Forest Biomass and Conventional Harvesting Effects on Estimated Erosion, Best Management Practice Implementation, Ground Cover, and Residual Woody Debris in Virginia

“…Garren et al [23] found similar results to Hawks et al [24] and Barrett et al [22] in the Mountains of Virginia. However, more significant differences between biomass and conventional sites were detected, likely due to the higher potential for negative site impacts from forest harvesting operations in topographically challenging mountainous regions [23].…”

“…There were also no significant differences in BMP implementation rates, which were significant predictors of site-wide erosion rate estimates, indicating that BMPs were effective at controlling potential erosion on both conventional and biomass harvest sites [22]. Hawks et al (2023) [24] and Garren et al (2022) [23] conducted similar studies in the Coastal Plain and Mountains of Virginia, respectively. Hawks et al [24] found significantly less area of light slash and piles and significantly more area of bare soil on biomass sites than on conventional sites.…”

“…However, there are differences between biomass and conventional harvests that could necessitate additional environmental protection measures. By definition, biomass harvests obviously reduce post-harvest residual woody debris (slash) [20][21][22][23][24]. Slash is commonly used as a cover BMP for erosion control, as well as limiting unauthorized site access [9,[25][26][27][28][29].…”

Harvesting Losses for a Cut-and-Chip Harvesting System Operating in Willow Short-Rotation Coppice

“…In forestry, woody debris left behind after harvesting operations is commonly referred to as slash or harvesting residues [28]. In agriculture, crop materials lost to any factor are referred to as losses, which may be partitioned due to cause (e.g., weather, disease, harvesting, and storage) or type (merchantable, non-merchantable, drop, etc.)…”

GIS-based decision support systems to minimise soil impacts in logging operations

“…Application of logging residues on forwarder trails after temporary machine passages, to close water crossings, has been shown to be a costeffective best management practice (BMP) in the US to reduce total suspended solids transported to surface waters (Wear et al 2013). Proper implementation of BMPs, in harvesting sites, was shown to be a significant factor affecting erosion rate in these sites (Garren et al 2022).…”