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Linda Joyce
Rocky Mountain Research Station
240 West Prospect
Fort Collins, CO 80526
Phone: 970-498-2560
 United States Department of Agriculture Forest Service.USDA logo which links to the department's national site.Forest Service logo which links to the agency's national site.
Bio-Based Products and Bio-Energy Program
Issues are forests overstocked with large amounts of small-diameter trees that have heightened fire danger, threatened biodiversity, and are more costly in terms of management
Determine the ecological role of small-diameter trees in Rocky Mountain ecosystems
Develop efficient and ecologically sound harvest techniques for small-diameter trees and estimate the impact of vegetation management on the long-term availability of small-diameter trees
Quantify quality of wood from small-diameter trees and management’s influence on that quality
Small Diameter Utilization Program Four Corners Sustainable Forests Partnership


Production rates, environmental impacts of using ATVs to harvest small diameter material

Many restoration prescriptions specify the removal of numerous understory trees (less than 8 inches in diameter) to reduce forest density and eliminate ladder fuels that contribute to crown fires. Conventional harvesting equipment has been designed primarily for handling large saw log-size trees and is therefore very inefficient when used to manipulate and move numerous small trees. This study examined the utility of a small-wheeled skidding arch that can be attached to a four-wheel-drive ATV, documented the production rates using such equipment in a forest thinning operation, and monitored the environmental impact of such a forest thinning operation conducted on the Fraser Experimental Forest. Guidelines for the use of such equipment will be developed. Skidding arch has been demonstrated at the Smallwood Conference in Albuquerque and local field trips.

We designed, constructed and successfully tested a small-wheeled skidding arch that can be attached to a four-wheel-drive ATV and used to skid small diameter logs (see Figure below). The arch allows one end of attached logs to be raised off the ground allowing the ATV to easily pull the log out of the forest. Raising the log also reduces damage to the forest floor. The results of a replicated time/motion study of the ATV arch that we conducted in lodgepole pine thinning plots at the Fraser Experimental Forest in central Colorado indicate that productions rates of up to four cords per day are possible over skidding distances up to 1400 ft. The equipment had negligible effects on soil compaction and water absorption capacity.

To Reduce Catastrophic Fires and Produce a Long-term Biomass Supply for Energy Production

In a cooperative study with Oak Ridge National Lab, Shepperd and others explored a modeling approach to evaluate management necessary to reduce catastrophic fires and produce a long-term biomass supply for energy production in forests in California, Southwest, and the Front Range of Colorado.

Graham, R.L.; Huff, D.D.; Kaufmann, M.R.; Shepperd, W.D.; Troendle, C.A.; Lynch, D.; Sheehan, J. 1999. Bioenergy and watershed restoration in the mountainous regions of the West: What are the environmental/community issues? IN: Proceedings: Bioenergy 98 Conference; 1998 October 7; Madison, WI. Web published at:

Wood consumption in Colorado

One aspect of the utilization of small-diameter material is the availability of markets for products. Lynch and Mackes have conducted research estimating the kinds, uses, amount and retail value of wood products consumed in Colorado. From their research, it is evident that Colorado has a substantial wood market and is dependent on other states and countries for this wood consumed. We worked with Dr. Dennis Lynch and Dr. Kurt Mackes to publish their work on wood consumption in Colorado.

Lynch, D. L.; Mackes, K. 2001. Wood Use in Colorado at the Turn of the Twenty-First Century. Research Paper RMRS-RP-32. Fort Collins, CO: USDA FS Rocky Mountain Research Station, 23 p. See publication at:

Opportunities for Making Wood Products from Small Diameter Trees in Colorado

Experimental ecological restoration studies using thinning and prescribed fire have been conducted at several locations across Colorado during the past 5 years to determin if high-risk areas could be treated to improve forest health and reduce the potential for catastrophic fires. These studies establishe htat 80 to 96 percent of the trees removed were between 5 and 11.9 inces in diameter. A search for opportunities to use small diameter trees from these projects was conducted as part of an effort to improve the financial feasibility of forest restoration. The potential opportunities for using wood exist in both existing products, processes, and technology, and in new products, processes and technology.

Lynch, D.L.; Mackes, K.H. 2002. Opportunities for making wood products from small diameter trees in Colorado. Res. Pap. RMRS-RP-37. Fort Collins, CO: USDA FS Rocky Mountain Research Station, 23 p. See publication at:

Mechanical Testing of Wood Pieces produced from small Diameter Trees harvested from Ponderosa Pine Forests along the Front Range of Colorado

Planned forest restoration activities along the Front Range of Colorado will result in the harvest of large volumes of small diameter trees. This study will address the existing questions about the properties of the wood cut from these trees, due to the unknown effects on wood quality resulting from growth conditions found in the forests where they grow. Knowledge of the mechanical properties of this wood is critical for use in the structural applications.

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