Effectiveness monitoring for biodiversity: comparing 15 year old structural retention harvest areas to fires in boreal aspen

Abstract

Convergence of species composition in regenerating harvested areas and naturally disturbed forest is a critical component of forest management modeled after natural disturbances. We assessed convergence of birds, plants, and habitat structures in aspen (Populus tremuloides) stands harvested with structural retention by Alberta-Pacific Forest Industries Inc. (Al-Pac) 15 years ago with similar aged fire area, and examined a chronosequence of younger and older burned aspen stands from Alberta Biodiversity Monitoring Institute (ABMI) sites. Most habitat structures and many bird and plant species in the 15 year harvest areas were at levels similar to 20–40 year or >40 year fire areas. Snags, moss, and lichen cover, and a few groups of species were at lower levels in the harvest areas than comparable aged fire areas or older stands. Agglomerative clustering showed the plant community to be most similar to >40 year burned stands, with the bird community intermediate between >20 year and <20 year fire areas. A novel likelihood-based analysis of species estimated the 15 year harvest areas to have a community similar to forest sites with 36.8% human footprint, indicating substantial recovery of the harvest areas. Harvesting aspen stands with structural retention appears to be effective at allowing most biodiversity components to recover rapidly.