Title: Evaluation of mountain pine beetle activity on the Black Hills National Forest
Description: Mountain pine beetle populations have been increasing in the Black Hills over the last 3 years. In 1998, 1999, and 2000, aerial surveys have detected a large mountain pine beetle infestation in the Beaver Park area on the Northern Hills Ranger District. Ground surveys found 41.4 trees per acre killed on average over the last 3 years, with approximately 61% of these trees being currently infested. Also, brood sampling continues to indicate that beetle populations are still increasing in the area. Three years ago nearly 70% of the forested land in the Beaver Park area was classified in the moderate to high stand susceptibility categories. Stand susceptibility is being reduced as much of the basal area has been decreased by beetle-caused tree mortality. However, because there has been no treatment, there continues to be epidemic mountain pine beetle populations and associated high levels of tree mortality in the Beaver Park area. In addition to the mountain pine beetle situation in Beaver Park, pockets of beetle-killed trees have been detected from aerial survey in the Bear Mountain and Steamboat Rock areas. Ground surveys in these areas found an average of 8.2 and 7.3 trees per acre killed over the last 3 years, respectively. More than 45% of these trees are currently infested. Brood sampling in both areas suggest beetle populations are increasing. Relatively few currently infested trees were found in the Pactola Lake, Sheridan Lake, and Deerfield Recreation Areas. Strategies for dealing with the mountain pine beetle include: do nothing, silvicultural treatments, sanitation/salvage harvesting, infested tree treatment, and individual tree protection. Although the part of the Beaver Park area that has been classified as roadless is off limit to treatment, a full range of treatments should be considered in the surrounding areas to limit the continued expansion of the mountain pine beetle epidemic in this area. Similarly, a combination of silvicultural treatments and sanitation harvesting or mechanical treatment is recommended for the Bear Mountain and Steamboat Rock areas. Continued sanitation removal of infested trees within the recreation areas is recommended.
Subjects: Mountain pine beetle
Places: Black Hills National Forest (S.D. and Wyo.)