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Abstract
The recent encroachment of piñon (
Pinus edulis) and juniper trees (
Juniperus osteosperma) into historically shrub- and grass-dominated landscapes has caused major changes in ecosystem structure and function, including dramatic changes in fuel structure and fire regimes. Such encroachment is currently occurring on thousands of acres on the Shivwits Plateau in northwestern Arizona and land managers are seeking effective techniques to restore these areas to pre-invasion conditions and reduce the threat of high severity crown fires. A study was established on the Shivwits Plateau to test the effectiveness of three thinning techniques for reducing the density of recently established piñon and juniper trees and to assess changes to the fuelbed structure. The thinning treatments were: (1) cut and leave; (2) cut, buck and scatter; and (3) herbicide. The line-point intercept method was used to characterize changes in the fuelbed structure. Belt transects were used to quantify tree density. Responses of the shrubs and suffrutescent plants (herein collectively referred to as ‘shrubs’) are reported. Generally, there was more live shrub cover in the treatment units versus the control units. In addition, the mechanical treatments added woody fuels to the initially sparse sites. These two structural changes are expected to help to carry surface fire through the treated areas.
Parent Publication
Citation
Smith, Helen Y.; Hood, Sharon; Brooks, Matt; Matchett, JR; Deuser, Curt. 2006. Response of Fuelbed Characteristics to Restoration Treatments in Pinyon-Juniper-Encroached Shrublands on the Shivwits Plateau, Arizona. In: Andrews, Patricia L.; Butler, Bret W., comps. 2006. Fuels Management-How to Measure Success: Conference Proceedings. 28-30 March 2006; Portland, OR. Proceedings RMRS-P-41. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 513-521
