Recovery rates of white spruce and balsam fir on seismic lines in NW Alberta, Canada

Anthropogenic disturbances have significantly impacted Alberta's boreal forest, particularly through an extensive network of seismic lines created during oil and gas exploration. These linear disturbances (3-10 m wide) fragment woodland caribou habitat, leading to the loss and degradation of ecosystem services. Natural tree regeneration on seismic lines can help reduce predator presence in caribou habitats; thus, achieving a minimum density of 2000 stems per hectare (sph) with trees at least 3 m tall is considered essential for recovery. However, there are currently no regulatory mandates for seismic line restoration, resulting in limited understanding of forest recovery dynamics, particularly tree regrowth rates. This study aimed to address this gap by comparing the growth of two common conifer species—white spruce and balsam fir—on seismic lines versus adjacent mature forests in northwest Alberta's upland conifer mixedwood stands. Findings indicate that both species may take approximately 30 to 50 years to achieve the 3 m height and 2000 sph target necessary for potential predator-use reduction. While it remains uncertain how this regeneration rate will affect woodland caribou habitat restoration, further investigations through modeling exercises will explore its implications for land use planning.