Brian Aukema, baukema@nrcan.gc.ca1, Allan Carroll2, Jun Zhu3, Kenneth F. Raffa, Raffa@entomology.wisc.edu4, Theodore Sickley5, and Steve Taylor2. (1) Canadian Forest Service & University of Northern British Columbia, 3333 University Way, Prince George, BC, Canada, (2) Canadian Forest Service, Pacific Forestry Centre, 506 W. Burnside Road, Victoria, BC, (3) University of Wisconsin, Department of Statistics, 1300 University Ave, Madison, WI, (4) University of Wisconsin, Department of Entomology, 1630 Linden Drive, 345 Russell Labs, Madison, WI, (5) University of Wisconsin, Forest Ecology and Management, 1630 Linden Drive, Madison, WI
The ongoing outbreak of mountain pine beetle, Dendroctonus ponderosae Hopkins in British Columbia, Canada, now covers almost 9 million ha in area. This area envelops many land tenures, from managed forest to protected areas. We present a landscape-level analysis of the development of the current outbreak, using aerial assessments of tree mortality as proxies for insect population density. We had two goals: first, to examine the pattern of outbreak initiation; second, to determine whether these patterns were associated with land tenures characterized by historically low management activity directed against bark beetles. An aspatial cluster analysis of time series from 1990 to 2003 revealed four distinct time series patterns across the province. Each pattern shared a trend of increasing mountain pine beetle populations. Plotting the geographical locations of each temporal pattern on a map revealed that the outbreak first occurred in an area of west-central British Columbia. The land tenure in this area was primarily park and protected area. However, the map further revealed that many localized infestations erupted in geographically disjunct areas, especially in the southern portion of the province, in areas not associated with parks. Bark beetle outbreaks are caused by a multitude of biotic and abiotic factors, and it would be incorrect to blame the current outbreak solely on land tenure.
Species 1: Coleoptera Curculionidae
Dendroctonus ponderosae (mountain pine beetle)