Evaluation of the spruce, mountain pine, and douglas-fir beetle populations on Carter Mountain, Shoshone National Forest, Wyoming

Description:

Concurent epidemics of spruce, mountain pine, and Douglas-fir beetle in the same area is at best extremely rare. This is the situation in the Carter Mountain assessment area, although each beetle epidemic is in a different phase. A very intense and extensive epidemic of spruce beetle began west of the Continental Divide, which was discovered in 1999 on northwestern portions of the Shoshone National Forest and adjacent lands. Epidemic beetle populations made their way to the east, arriving around the year 2000 in the Carter Mountain assessment area. By the fall of 2003 or 2004, the spruce beetle epidemic will have run its course through the forests there, resulting in the death of almost all of the Engelmann spruce larger than 5 inches DBH and some smaller diameter trees. This mortality has occurred everywhere, regardless of tree density or species composition of the sites in which the attacked spruce had been living. Because the spruce beetle has killed much of the overstory, the remaining live forest canopy is composed primarily of lodgepole, limber, and white bark pines and Douglas-fir, with some subalpine fir and a smaller amount of aspen. Rising beetle epidemics in the pines and Douglas-fir threaten to further reduce the forest cover and degrade stands managed for fiber production. Plot, transect and walk through survey data are presented documenting forest insect and tree-disease conditions in the assessment area. Predictions are made as to the future impacts from these conditions. Recommendations are presented that address impacts consistent with management objectives.

subjects: Spruce beetle,  Mountain pine beetle,  Douglas fir beetle

Places: Wyoming,  Shoshone National Forest