Study Sites Selected

Fuels data used in developing this photo guide were collected from a number of stands in each of the three major forest types located throughout Utah and in central Idaho. All three forest types have experienced varying levels of bark beetle-caused tree mortality since the late 1980’s. The primary bark beetle species infesting Englemann spruce, Douglas-fir, and lodgepole pine were spruce beetle (Dendroctonus rufipennis Kirby), Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins), and mountain pine beetle (Dendroctonus ponderosae Hopkins), respectively.

Selected stands in each forest type were classified as either endemic, epidemic, or post-outbreak. Stands with endemic populations of bark beetles were defined as those having no evidence of current or older tree mortality attributed to bark beetle infestation. Stands with epidemic populations of bark beetles were defined as those having increasing levels of tree mortality and/or at least four clumps of five or more standing infested trees per hectare. Only plots with at least one infested tree were sampled in epidemic stands. Post-epidemic stands had more than 60% host tree mortality that was generally older than five years. However, only plots with greater than 80% host mortality were sampled in post-epidemic stands.

The specific locations of stands sampled by bark beetle population level in each forest type is provided in the following table.


Locations of stands sampled by bark beetle population level in each forest type.
Forest Type Bark Beetle Population Level
Endemic Epidemic Post-epidemic
Engelmann spruce *LaSal Mountains Fishlake Hightop LaSal Mountains Fishlake Hightop LaSal Mountains Fishlake Hightop
Douglas-fir S. Wasatch Mountains
Uinta Mountains (E)
S. Wasatch Mountains
Uinta Mountains (E)
S. Wasatch Mountains
Uinta Mountains (E)
Lodgepole pine Uinta Mountains (W)
Sawtooth NRA
Uinta Mountains (W)
Sawtooth NRA
Uinta Mountains (E)
*LaSal Mountains: Manti-LaSal National Forest, southeastern Utah; Fishlake Hightop: Fishlake National Forest, southcentral Utah; Wasatch Plateau: Manti-LaSal National Forest, southcentral Utah; Uinta Mountains (E): Ashley National Forest, northeastern Utah; Uinta Mountains (W) and S. Wasatch Mountains: Uinta-Wasatch-Cache National Forest, northern Utah; Sawtooth NRA, central Idaho;