Influence of Fires, Fungi and Mountain Pine Beetles on Development of a Lodgepole Pine Forest in South-Central Oregon

Abstract

Virtually pure lodgepole pine stands form an edaphic climax community over large areas of the infertile pumice plateau of south-central Oregon. During our ongoing studies on the dynamics of these forest we developed the scenario that periodic fires create fungal infection courts in damaged roots; in time, advanced decay develops in the butts and stems of these trees. The mountain pine beetle preferentially selects and kills these trees during the flight season. As these outbreaks develop, additional uninfected trees are attacked. In time, the stage is set for subsequent fires as needles drop, snags fall, and logs decay.