Infestation Phases and Impacts of Dryocoetes confusus in Subalpine Fir Forests of Southern British Columbia

Subalpine fir mortality and stand decline are increasingly evident in British Columbia (B.C.). This long-term study confirmed Dryocoetes confusus to be the major disturbance agent high-elevation subalpine forests, killing over two-thirds of eleven one-hectare plots. D. infestations mature stands can described as early-, mid-, or late-phase. The transition from early- through late-phase is characterized by a lowered stem density high levels attack remove largest trees, while other factors kill smaller trees. Initially, live activity varied among By final assessment, very little difference was observed stems per hectare. Mortality all ranged 0.5% 5% annually, reaching 80% in-stand with >6 times more dead than volume. When reduced <400 sph, rate declined. Cumulative increased average gap size plots 11 m2 18 m2. Our also showed that might able switch univoltine life cycle, taking advantage warmer longer growing seasons that, part, could explain rapid increase stands.