Forest Investment Account

Abstract of FII Project R04-030

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Spatial and temporal patterns of western spruce budworm outbreaks in Southern British Columbia

Author(s): MacLauchlan, Lorraine (BC Ministry of Forests)
Subject: Entomology, Forestry, Silviculture/Forest Management Systems
Series: Forest Investment Account (FIA) - Forest Science Program


Western spruce budworm occurs throughout most Douglas-fir types in southern B.C. Outbreaks cover large areas of susceptible forest, and cause growth loss, defects, regeneration delays, and mortality. Various silvicultural treatments are available for long-term management, but during outbreaks direct control is the most effective treatment to mitigate losses. Dr. Maclauchlan has collected over 1,600 tree cores from 167 sites in the Kamloops Forest Region that have been measured, analysed and a chronology built. Another data set has been produced from over 2,500 cores and disks collected by Dr. Rene Alfaro, Canadian Forest Service, from budworm impacted stands throughout the Fraser Canyon and western portions of the Region. These data sets will be combined, and the results will provide forest managers with estimates of potential volume loss and historical outbreak information for much of southern B.C. Budworm risk analysis will assist in deciding the economic and biological benefits of direct control.

For further information, please contact Lorraine Maclauchlan, BC Ministry of Forests (

Updated September 08, 2005 

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