Vegetation Recovery on Low Impact Seismic Lines in Albertas Oil Sands and Visual Obstruction of Wolves (Canis lupus) and Woodland Caribou (Rangifer tarandus caribou)

Low-Impact Seismic (LIS) exploration techniques are being increasingly used in northeastern Alberta, Canada to explore for in-situ oil sands deposits. These narrow (2-4-m wide), meandering man-made linear features are often closely spaced (50-100 m apart) in a grid pattern. They were developed to reduce loss of merchantable trees, minimize habitat loss, and minimize loss of vegetation cover that would open up lines of sight that could result in increased mortality for some animals. This 3-year study used a paired sampling design to measure the extent of vegetation recovery and visual obstruction of wolves (Canis lupus) and caribou (Rangifer tarandus) on 7-9-year-old LIS lines in the Boreal Plains of northeastern Alberta.

In spite of their narrow widths, the dense spacing of LIS can result in a substantial overall physical surface footprint of >10% within a given mineral surface lease. Mean vegetation regrowth cover from 0-2 m above ground was significantly greater on control transects than on paired LIS transects for most ecosites, but particularly in deciduous sites. Bogs and poor fens had a relatively slower vegetation regrowth above 1 m. Results suggest that after 7 to 9 years, visual vegetation obstruction may be higher for wolves than for woodland caribou, likely due to the shorter stature of wolves. Reclamation and monitoring initiatives should focus on LIS features showing poor vegetation re-growth and should include vegetation obstruction metrics.