Search

..................................

Select Level of Detail

At a Glance

General

Technical

............................

+ Forest Resources - Logging Residues

............................

Access BioWeb Content

Search

Explore By Topic

Browse Index

............................

BioWeb Glossary

Search

Alphabetical Listing

............................

Contributors Log in

bioweb.sungrant.org » Technical » Biomass Resources » Forest Resources » Logging Residues

Logging Residues	Printer Friendly

The U.S. forestry industry, in the process of harvesting and converting wood into consumer products, generates a number of residue and waste materials that could be used for bioenergy and bioproducts. Forest industry resources include those resulting from operations within forest and timberland areas, as well as materials generated in the conversion of wood into intermediate and final products such a lumber, paper, and furniture (i.e., mill residues).    Among the resources obtained from the harvest of forest and timberland areas are logging residues. Logging residues are the portions of harvested trees that are not utilized and that are left in the woods after operations. Logging residue data is publicly available online through the Timber Product Output (TPO) database (http://www.fia.fs.fed.us) compiled by the USDA Forest Service Forest Inventory and Analysis Program (FIA) which is charged with tracking and reporting on the fate of wood that is harvested from U.S. forests. The FIA collects forest residue data through surveys and questionnaires sent to forest owners and harvesters, and by on-site measurements of the material felled and removed and/or left during harvesting operations. The TPO database provides estimates of county quantities of logging residues generated. Data is provided by inventory source (i.e., total and growing stock), by tree species, and by land ownership class in cubic feet and board feet.   Estimated logging residue quantities for the RPA (Resource Planning Act) survey year 2007 by ownership class and tree class are presented in table 1. Approximately 4.51 billion ft3 (63.04 million dry tons) of logging residues were generated from all sources. About 44% of the residues came from softwood tree species and the remainder from hardwood tree species. About 8% of the material came from national forests and other public lands. The distribution of logging residues generated in RPA survey year 2007 is shown in figure 1. The FIA data form the basis of the estimated available logging residue quantities found in a number of studies such as Perlack, 2005; Southern States Energy Board, 2006; Western Governors’ Association, 2006; Encyclopedia of Southern Bioenergy Resources, 2006; 25x25 Initiative, 2006; and Walsh, 2007.                                 The TPO database is limited to historical data and does not project potential quantities of logging residues for future time frames. The Forest and Rangeland Renewable Resources Planning Act (RPA) of 1974 directs the Forest Service to conduct a study every 10 years that projects the future cost and availability of timber products, evaluates emerging issues, and examines impacts of policy options. According to the last full RPA assessment (Haynes, 2003), logging residues have been a declining portion of the total removals from the growing stock inventory decreasing from 9.8 to 6.4% of softwood removals and 22.2 to 12.4% of hardwood removals between the years 1952 and 1997. This trend is projected to continue with logging residues as a percent of softwood removals declining to 6% and to 9% for hardwood removals by 2050. This trend is due to higher prices which make it more economical to remove lower quality material, to changes in harvesting methods, and to the increased use of fuelwood. The analysis accounts only for logging residues from growing stock. Of the 3.25 billion cubic feet of logging residues generated in RPA survey year 2002, 41% (1.34 billion cubic feet) were from growing stock sources, with the remainder from other sources. Using the USDA Forest Service FIA logging residue data, and projected harvests and percent logging residue removals from the RPA assessment, Perlack (2005) estimated the availability of 46.4 million dry tons of logging residues by mid-century, but conducted no economic analysis.   Few studies attempt to estimate supply curves (i.e., quantities available as a function of price) for logging residues for either current or future time frames, but costs are thought to be relatively similar to pulpwood harvest and transport costs. Some analysts have constructed local or regional supply curves. Kerstetter (2001) estimated the availability of 3.52 million dry tons of logging residues in OR, WA, ID, and MT. He estimated that the cost of recovering the residues ranged from $32.40 to $92.23/dry ton depending on the slope of the site, the size of the pieces recovered, and the distance the material is skidded to a road. For pieces of greater than 15 ft3 and slopes of less than 35 percent, the estimated recovery costs were $32.40 to $41.64/dt. The Antares Group (1999) estimated the availability of 111 million green tons of wood wastes (combined forest residues, mill residues and urban wood wastes of which 72.2 million green tons were forest residues) at prices of less than $4.00/million Btu, but did not separate the feedstock sources in their report. Walsh (2000) estimated state forest residue supply curves (including logging residues) and summed the state data to obtain total U.S. forest residue quantities at several prices (e.g., 23.7, 34.8, and 44.9 million dry tons available at delivered prices of $30/dt, $40/dt, and $50/dt respectively).   Walsh (2007), using RPA assessment projections and FIA estimates of current logging residue quantities and distribution, estimated future logging residue collection cost schedules at several price levels (table 2). Future quantity estimates were based on the projected changes in regional softwood and hardwood timber harvest quantities from forest lands (Haynes, 2003; Haynes, 2007). Estimated costs of collecting logging residues were based on a regional distribution of logging residue collection costs obtained from a somewhat updated version of a model originally developed by McQuillan (1988). The model includes forest inventory data, logging and chipping costs, wood types, site accessibility, site slope, and equipment operability constraints to estimate nine regional supply schedules for softwood and hardwood chips for the base (1983) and future years. The analysis suffers from the inability to fully update the original economic model, to fully account for structural changes in the timber industry or shifts in stumpage prices over time, to fully disaggregate regional data to county data, and to account for new harvest and collection technologies. It should be noted that collection costs are not the same as the market prices paid for the materials which fluctuate in response to supply and demand conditions (e.g., changes in housing construction) and which typically vary from year to year. For example, delivered (to the mill) pulpwood prices for the first quarter of 2007 were reported to be $60 to $70/dry ton in the East and around $100/dry ton in the Pacific Northwest (International Woodfiber Report, RISI).           New approaches to removing residues and small diameter trees are being evaluated (Rummer, 2004; Rawlings, 2004). Integrated harvesting systems (i.e., harvesting of forest biomass in a single pass operation such that wood for fuel can be produced with conventional forest products; Puttock, 1995) could alter both the quantities of logging residues, as well as their costs. The addition of on-site chippers to the standard harvest equipment complement has been shown to increase the amounts of biomass (logging residues and understory) that can be recovered from a site with marginal increases in costs (Westbrook, 2006). However, harvest and collection costs are site specific and differ not only due to regional and local differences in input costs (i.e., labor, fuel, equipment, etc.) and machinery complements (type used, cost and productivity), but also are highly dependent on site characteristics (slope, distance to road), material characteristics (tree size and species), harvest type (clearcut, thinning, whole tree, residues), condition of trees (standing healthy trees, dead and downed trees), and material form (whole trees, chips, etc.) among other factors (Hartsough, 1990). Thus while results from the evaluation of new collection approaches at a single site under specific conditions are instructive, caution is warranted when extrapolating the results to other situations.

References
Antares Group, Biomass Residue Supply Curves for the United States, June 1999. Encyclopedia of Southern Bioenergy Resources, 2006, U.S.D.A. Forest Service, Southern Research Station, Forest Encyclopedia Network, http://www.forestencyclopedia.net. English, Burton C., Daniel G. De La Torre Ugarte, Kim Jensen, Chad Hellwinckel, Jamey Menard, Brad Wilson, Roland Roberts, and Marie Walsh, November 2006, 25% Renewable Energy for the United States by 2025: Agricultural and Economic Impacts, University of Tennessee, http://www.25x25.org. Hartsough, Bruce R. and Bryce J. Stokes, 1990, Comparison and feasibility of North American Methods for harvesting small trees and residues for energy, In Proceedings of the International Energy Agency, Task VI, Activity 3, Workshop, “Harvesting Small Trees and Forest Residues,” May 28, 1990, Copenhagen, Denmark. Haynes, Richard W., An Analysis of the Timber Situation in the United States: 1952 to 2050, USDA Forest Service, General Technical Report PNW-GTR-560, February 2003. Haynes, Richard W., Darius M. Adams, Ralph J. Alig, Peter J. Ince, John R. Mills, Xiaoping Zhou, 2007, The 2005 RPA Timber Assessment Update, General Technical Report PNW-GTR-699, USDA Forest Service, Pacific Northwest Research Station, Portland Oregon, 212 pages. International Woodfiber Report, RISI, www.risiinfo.com. Kerstetter, J., and J. Lyons, January 2001, Logging and Agricultural Residue Supply Curves for the Pacific Northwest, Washington State University Energy Program, Olympia, WA. McQuillan, A., K. Skog, T. Nagle, and R. Loveless, Marginal Cost Supply Curves for Utilizing Forest Waste Wood in the United States, Unpublished Manuscript, University of Montana, Missoula, February 1988. Perlack, Robert D., Lynn L. Wright, Anthony F. Turhollow, Robin L. Graham, Bryce J. Stokes, and Donald C. Erbach, Biomass as Feedstocks for a Bioenergy and Bioproducts Industry: The Technical Feasibility of A Billion-Ton Annual Supply, April 2005, ORNL/TM-2005/66. Puttock, G.D., 1995, Estimating cost for integrated harvesting and related forest management activities, Biomass and Bioenergy 8(2): 73-79. Rawlings, Craig, Bob Rummer, Chuck Seeley, Craig Thomas, Dave Morrison, Han-Sup Han, Levi Cheff, Dave Atkins, Dean Graham, and Keith Windell, December 2004, A study of how to decrease the costs of collecting, processing and transporting slash, Montana Community Development Corporation, Missoula, MT. Rummer, Bob, Dan Len, and Obie O’Brien, May 2004, Forest Residues Bundling Project-New Technology for Residue Removal, U.S.D.A. Forest Service, Southern Research Station, Smith, W. Brad, Factors and Equations to Estimate Forest Biomass in the North Central Region, U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station, Research Paper NC-268, October 1985. Southern States Energy Board, July 2006, American Energy Security-Building a bridge to energy independence and to a suitainable energy future. USDA Forest Service, Forest Inventory Analysis Timber Product Output Database, www.fia.fs.fed.us Walsh, Marie E., Robert L. Perlack, Anthony Turhollow, Daniel de la Torre Ugarte, Denny A. Becker, Robin L. Graham, Stephen E. Slinsky, and Daryll E. Ray, Biomass Feedstock Availability in the United States, Unpublished Oak Ridge National Laboratory Report, January, 2000. Walsh, Marie E., November 2007, Estimated U.S. Forest Residue Supply--Documentation of Methodology, Unpublished Manuscript. Westbrook, Michael D. Jr., W. Dale Greene, and Robert L. Izlar, 2006, Harvesting forest biomass by adding a small chipper to a ground-based tree-length Southern pine operation, Center for Forest Business, Warnell School of Forestry and Natural Resources, University of Georgia, www.forestry.uga.edu. Western Governors’ Association, January 2006, Clean and Diversified Energy Initiative, Biomass Task Force Report, Supply Addendum.