} 



ABSTRACT 



The mountain pine beetle depletes Rocky Mountain 

 lodgepole pine stands by removing periodically the largest, 

 most vigorous trees. Some stands are replaced by suc- 

 ceeding species in 80 to 100 years. 



Intensities of mountain pine beetle and dwarfmistletoe 

 damage are influenced by forest associations and elevation. 

 Dwarfmistletoe infection reduces phloem depth and probably 

 results in lower mountain pine beetle brood production. 



The probability of lodgepole pine surviving to 16 inches 

 d.b.h. is about two out of three in the Abies lasiocarpa/Vac- 

 cinium scoparium association, but only one out of four in the 

 Abies lasiocarpa/Pachistima myrsinites association. The 

 latter association offers the greatest risk to lodgepole pine. 

 More effective beetle control and alternatives such as type 

 conversion, shorter rotations, mixing species, and develop- 

 ing better size and age class distribution must be considered. 



