Caribou Conservation: Restoring Trees on Seismic Lines in Alberta, Canada

Seismic lines, narrow linear clearings used for petroleum exploration in Alberta’s boreal forest, experience poor forest regeneration post-disturbance, and treatments to reforest them are expensive. To better target reforestation efforts, this study tested the effectiveness of Mechanical Site Preparation (MSP) treatments (mounding and ripping) across three restoration projects (LiDea 1, LiDea1, and CNRL Kirby). Treated seismic lines were compared against untreated lines and adjacent undisturbed reference stands, and results were stratified by ecotype.

Mounding and ripping significantly improved tree regeneration on seismic lines. Treated seismic lines had higher stem densities than both untreated lines and adjacent undisturbed forest stands, even though treatments were applied much more recently (3.8 years since treatment on treated seismic lines, compared to 22 years since disturbance on untreated seismic lines). On average, treated lines had 12,290 regenerating tree stems/ha, which is 1.6-times more than untreated lines (7680 stems/ha) and 1.5-times more than the adjacent undisturbed forest (8240 stems/ha). While this trend held across all four ecosites, the increase in stem density on treated poor fens was not statistically significant, suggesting site-specific variability in treatment effectiveness.