Predicting Patterns of Regeneration on Seismic Lines to Inform Restoration Planning in Boreal Forest Habitats

Abstract

Mapping of oil reserves involves the use of seismic lines (linear disturbances) to determine size of reserves. These linear disturbances fragment forests and in many cases fail to regenerate trees even decades following their use. With the continued rise in anthropogenic disturbances, regeneration of seismic lines is necessary for the conservation of biodiversity. Little is known, however, about how local and landscape factors affect natural recovery of trees and shrubs on seismic lines. I investigate factors affecting early forest regeneration using LiDAR, forest stand databases and a disturbance inventory of 4350 km of seismic lines over a 1,806 km2 region (density of 2.4 km/km2) of northeast Alberta. Regeneration to a height of at least 3 m or to 50% of the adjacent stand were inversely related to terrain wetness, line width, distance from roads (as a proxy for human use of lines), and the lowland ecosites. Overall, terrain wetness and the presence of fen ecosites had the strongest negative effect on regeneration patterns; the wettest sites fail to recover even after 50 years post-disturbance. Predictions of future regeneration rates on existing lines suggested that up to 50% of existing linear disturbance footprints in this boreal landscape will remain un-regenerated 50 years later. I then used predictions of vegetation regeneration on seismic lines to 3 m height 10, 30, and 50 years post-disturbance for optimizing restoration to benefit woodland caribou. I incorporated costs for bitumen pay thickness, linear feature density, distance to nearest road and regeneration probability, while targeting restoration priority areas for woodland caribou. Marxan with Zones was used to configure seismic lines into 3 zones: active restoration (reclamation), passive restoration (natural regeneration), and available. Through prioritization of restoration of seismic lines, millions of dollars can be saved while improving woodland caribou habitat and reducing the risk of re-disturbance from future oil sands development. This thesis effectively demonstrates methodology to assess the regeneration of vegetation on seismic lines and quantitatively optimize restoration of these disturbances. This work can directly support landscape management initiatives concerning linear footprint within Alberta Environment and Sustainable Resource Development.