The degree and extent of soil compaction, which may reduce productivity of forest soils, is believed to vary by the type of harvesting system, and a field-based study was conducted to compare soil compaction from cut-to-length (CTL) and whole-tree (WT) harvesting operations. The CTL harvesting system used less area to transport logs to the landings than did the WT harvesting system (19%–20% vs. 24%–25%). At high soil moisture levels (25%–30%), both CTL and WT harvestings caused a significant increase of soil resistance to penetration (SRP) and bulk density (BD) in the track compared with the undisturbed area (p < 0.05). In the center of trails, however, only WT harvesting resulted in a significant increase of SRP and BD compared with the undisturbed area (p < 0.05). Slash covered 69% of the forwarding trail area in the CTL harvesting units; 37% was covered by heavy slash (40 kg·m^–2) while 32% was covered by light slash (7.3 kg·m^–2). Heavy slash was more effective in reducing soil compaction in the CTL units (p < 0.05). Prediction models were developed that can be used to estimate percent increases in SRP and BD over undisturbed areas for both CTL and WT harvesting systems.

Damage to residual trees from commercial thinning was characterized and compared among four common harvesting systems in western Oregon: tractor, cut-to-length, skyline, and helicopter. Six young (30- to 50-yr-old) Douglas-fir (Pseudotsuga menziesii) stands with various residual densities were studied: Scarring was the most typical damage to crop trees, accounting for 90% of the total damage in most cases. Damage levels greatly decreased as the minimum scar size that defines damage was increased. Scarring by ground-based systems was more severe: scars were larger, and gouge and root damage were more prevalent than in skyline and helicopter systems. Damaged trees were concentrated within 15 ft of skid trails or skyline corridor centerlines. In the cut-to-length system, the harvester caused more wounding (70%) to crop trees than did the forwarder (30%), but forwarder scars were larger and sustained severe gouging. Recommendations for minimizing stand damage are included. West. J. Appl. For. 15(1):27-33.

The Waste to Wisdom project was part of the Biomass Research and Development Initiative (BRDI) and funded by the Department of Energy (DE-EE0006297) at an amount of $5.8 million. Our interdisciplinary research team, consisting of academics, business professionals, and land managers, worked together for about four years (September 2013 to December 2017) to: 1) conduct field-based experiments to develop innovative tools and systems that improve the economics, accessibility, and production of quality feedstocks from forest residues, 2) develop and test stand-alone in-woods or near-the-forest biomass conversion technologies (BCTs) for the production of biochar, torrefied wood, and briquettes, and 3) perform analyses to evaluate the economic feasibility of commercial deployment of BCTs and to quantify the life cycle economic and environmental benefits of utilizing forest residues with BCTs for the production of bioenergy and bioproducts. The research papers presented in this Special Issue cover key aspects of the research efforts and findings made by the project team. We encourage the audience to visit the project web site (http://wastetowisdom.com/) to learn more about the team’s research on feedstock development, biomass conversion technologies, and the financial and environmental benefits of utilizing forest residues for production of bioenergy and biobased products. Keywords: Air quality, Biomass conversion technology, Forest harvesting, Woody biomass.

Many socioeconomic constraints exist for biomass removals from federal lands in the western U.S. We examine several issues of importance, including biomass supply chains and harvesting costs, innovative new uses for bioenergy products, and the policy framework in place to provide incentives for biomass use. Western states vary greatly in the extent and utilization of forest resources, the proportion of land under federal ownership, and community and stakeholder structure and dynamics. Our research—which focused on the socioeconomic factors associated with biomass removal, production, and use—identified several important trends. Long-term stewardship projects could play a role in influencing project economics while being conducive to private investment. State policies are likely to help guide the growth of biomass utilization for energy products. New markets and technologies, such as biofuels, for use in the aviation industry, torrefied wood, mobile pyrolysis, and wood coal cofiring could greatly change the landscape of biomass use. Social needs of residents in wildland urban interfaces will play an important role, especially in an era of megafires. All of these trends—including significant unknowns, like the volatile prices of fossil energy—are likely to affect the economics of biomass removal and use in western forests.