Canadian Forest Service Publications
Landscape-level analysis of mountain pine beetle in British Columbia: spatiotemporal development and spatial synchrony within the present outbreak. 2009. Aukema, B.H.; Carroll, A.L.; Zhu, J.; Raffa, K.F.; Sickley, T.A.; Taylor, S.W. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC. Mountain Pine Beetle Working Paper 2008-29. 22 p.
Year: 2009
Issued by: Pacific Forestry Centre
Catalog ID: 31186
Language: English
Series: Mountain Pine Beetle Working Paper (PFC - Victoria)
Availability: PDF (download)
Abstract
We present a landscape-level analysis of the epidemiology and spatiotemporal pattern of spread of the current outbreak of mountain pine beetle in British Columbia to the year 2003. Aerial survey assessments of tree mortality, projected onto discrete 12 × 12 km cells, were used as a proxy for insect population density. We examined whether the outbreak potentially originated from an epicentre and spread, or whether multiple localized populations erupted simultaneously at spatially disjunct locations. An aspatial cluster analysis of time series from 1990-2003 revealed four distinct time series patterns. Each time series demonstrated a general progression of increasing mountain pine beetle populations. Plotting the geographical locations of each temporal pattern revealed that the outbreak occurred first in west-central British Columbia and spread east. The plot further revealed many localized infestations erupted in geographically disjunct areas, especially in the southern portion of the province. Autologistic regression analyses indicated a significant, positive association between areas where the outbreak first occurred and conservation lands. For example, the delineated area of west-central British Columbia comprises three conservation parks and adjacent working forest. We further examined how population synchrony declines with distance at different population levels. Examination of the spatial dependence of temporal synchrony in population fluctuations during early, incipient years (i.e., 1990-1996) suggested that outbreaking mountain pine beetle populations are largely independent at scales > 200 km during non-epidemic periods. However, during epidemic years (i.e., 1999-2003), populations were clearly synchronous across the entire province, even at distances of up to 900 km. The epicentral pattern of population development can be used to identify and prioritize adjacent landscape units for both reactive and proactive management strategies intended to minimize mountain pine beetle impacts.