The mountain pine beetle in lodgepole pine forests /

Abstract

The mountain pine beetle deplete s 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 lasiocarpajVac"7 cinium scoparium association, but only one out of four in the Abies lasiocarpajPachistima 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.