Figure l.--Bark scuffing daiaage to residual ponderosa pine tree sus- 

 tained during the log skidding phase of a sanitation-salvage 

 cutting operation in western Montana. Largoly as a result of the 

 damage to the bole and the resultant decrease in vigor, the beetle 

 risk of the tree increased from moderate (Risk 2) in 1949 to high 

 (Risk 3) in 1953. (CdA 1637). 



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