Outbreak of Dendroctonus rufipennis in Alaska (US)
In Alaska (US), forests of Picea glauca and P. glauca x lutzii are subject to mortality from a variety of causes (e.g. wind, fire, pests). Among these, Dendroctonus rufipennis (EPPO A1 quarantine pest) is the most devastating. Ongoing and new infestations currently affect 283,500 ha of spruce in Alaska. A study was carried out in the Resurrection Creek river of the Chugach National Forest in Alaska, in order to assess the impact of an outbreak of D. rufipennis on tree mortality, stand structure, timber volume loss and succession of understory vegetation. In this area (1280 ha), 51 % of the P. glauca x lutzii, or nearly 90 % of the commercial stand volume was killed during a 16 year period (since 1976). The majority of the losses occurred in the first 10 years of the outbreak. In June 1984, a prescribed burn was conducted on a part of the studied area (610 ha) to improve habitat for moose. Forest structure changed with decreased tree density, and species richness declined significantly on the unburned, infested plots. On the burnt plots, although species richness did not change 7 years after the prescribed fire, species composition did change.
Sources
Holstein, E.H.; Werner, R.A.; Develice, R.L. (1995) Effects of a spruce beetle (Coleoptera: Scolytidae) outbreak and fire on Lutz spruce in Alaska.
Environmental Entomology, 24(6), 1539-1547.