Subalpine forest development following a blowdown in the Mount Zirkel Wilderness, Colorado

Dominik Kulakowski, University of Colorado Boulder
Thomas T. Veblen, University of Colorado Boulder

Abstract

We documented the occurrence of a 1934 blowdown in a subalpine forest in northwestern Colorado, USA. Prior to the blowdown, the stand was dominated by old-growth Picea engelmannii - Abies lasiocarpa forests. Although blowdowns are believed to trigger outbreaks of Dendroctonus rufipennis (spruce beetle), we found no detectable increase in beetle caused mortality. Forest recovery was by both release of the previously suppressed regeneration and by new seedling establishment. Both recovery pathways were dominated by Abies. The blowdown thus caused a shift in species dominance from Picea to Abies; 65 yr after the blowdown, the fallen logs and tip up mounds continue to provide favourable habitat for seedling establishment of both species. The present study shows that the legacy of blowdowns can influence forest dynamics for decades following the disturbance event.