Silviculturists are under increased pressure to develop treatments that increase resistance and resilience to the spruce beetle (Dendroctonus rufipennis Kirby). Multiple silvicultural systems (i.e., group selection, shelterwood with reserves, and others) have resulted in some short-term increases in resistance. However, less is known about how silvicultural systems, especially ones used over many decades, impact resilience; resilience is defined as a minimum amount of Engelmann spruce (Picea engelmannii Parry ex Engelm.) regeneration to ensure continuity of a spruce component in the future stand. To further explore these concepts, silviculturally treated and untreated stands were sampled after a recent landscape-scale spruce beetle epidemic in northern Utah on the Uinta-Wasatch-Cache National Forest. Both treated and untreated stands had no resistance to the spruce beetle but differed in their resilience. Treated stands had increased resilience due to greater and more consistent stocking of Engelmann spruce regeneration than the untreated stands. When silvicultural systems are developed, special attention should be paid to ensure that conditions created after harvests are conducive for regeneration of the desired species (spruce).
Bibliographical noteFunding Information:
Acknowledgments: We thank the numerous staff from the Heber-Kamas Ranger District who have been involved with the treatment of these stands throughout the years. Specifically, we acknowledge Jim Gibson for assistance with site selection, data acquisition, and field access, Lew Giles who was the Timber Sale Administrator, Northern Utah Shared Service Timber Sale Group, for tree marking, and Steve Munson for forest health consultation. Funding was provided from grants from the USDA National Needs Graduate Fellowship Competitive Grant 2011-38420-20087 and McIntire-Stennis Cooperative Forestry Research Program.
© 2017 Society of American Foresters.
- Dendroctonus rufipennis
- Engelmann spruce
- Spruce beetle