INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Stand recovery and self-organization following large-scale mountain pine beetle induced canopy mortality in northern forests
AMOROSO, MARIANO; COATES, DAVID; ASTRUP, RASMUS
Congreso; 9th International Conference on Dendrochronology; 2014
A mountain pine beetle (MPB) epidemic is currently ravaging large areas of interior British Columbia (BC), Canada with significant implications for ecosystem services including future timber supply and community economic stability. Information is needed on future stand dynamics in areas of impacted forests that are unlikely to be salvaged logged. Predicting how surviving trees in these areas respond and grow and thetiming and species composition of natural regeneration ingress is of critical importance for multiple forest values. We undertook a retrospective study in southeastern BC where an intense MPB epidemic peaked in 1979-1980. Our objective was to gain insight into stand recovery and stand self-organization as influenced by species-specific growth responses of different sized secondary structure trees (seedlings, saplings, and canopy trees surviving the epidemic) and post-beetle regeneration dynamics. MPB mortality rates, the percent of basal area killed by beetles, varied from 42 to 100%. In general, all surviving secondary structure released but the extentof growth release exhibited species variability. Ingress of natural regeneration was slow in the first few yearsafter MPB attack but there was a strong pulse of recruitment 10-20 years post disturbance which then slowed considerably. Nearly 30 years after the MPB attack, the stocking and composition of the understories have changed dramatically. Overall, the occurrence of the MPB epidemic resulted in more structurally and compositionally diverse stands leading to multiple successional pathways different from those of even-age pine dominated stands.