Alberta's forests are becoming increasingly disturbed and fragmented by the cumulative effects of anthropogenic disturbances exacerbated by the enduring footprint of seismic lines on the landscape. Forest harvesting and subsequent reforestation activities (e.g., site preparation and tree planting) may facilitate tree growth on seismic lines when forestry companies incorporate them into management areas. In this study, forest regeneration was assessed along transects on and off seismic lines within four cutblocks in northwestern Alberta. Tree, sapling, and shrub characteristics were measured, and tree cookies from a subset of trees on and off seismic lines were used to model height growth. No difference in total tree, sapling, or shrub counts on and off seismic lines was found although trees on seismic lines were growing at slightly slower rates compared to the adjacent cutblock, and Alnus viridis was more abundant on seismic lines. Our results suggest that, despite some species-level differences and modest differences in tree growth rates, trees on seismic lines within cutblocks are regenerating similarly to other trees growing in the post-harvest stand. These findings indicate that forest harvesting, and subsequent reforestation, could represent an important tool in conducting landscape-level restoration in mixedwood forests where seismic lines have not naturally recovered.

Seismic lines are narrow, linear corridors cleared through forests for oil and gas exploration. Their inconsistent recovery has led to Alberta’s forests being highly fragmented, resulting in the need for seismic line restoration programs and subsequent monitoring. Light detection and ranging (LiDAR) is becoming an increasingly popular technology for the fast and accurate measurement of forests. Mobile LiDAR scanners (MLS) are emerging as an alternative to traditional aerial LiDAR due to their increased point cloud density. To determine whether MLS could be effective for collecting vegetation data on seismic lines, we sampled 17 seismic lines using the Emesent Hovermap™ in leaf-on and leaf-off conditions. Processing the LiDAR data was conducted with GreenValley International’s LiDAR 360 software, and data derived from the point clouds were compared to physically measured field data. Overall, the tree detection algorithm was unsuccessful at accurately segmenting the point clouds. Complex vegetation environments on seismic lines, including small conifers with obscured stems or extremely dense and tall shrubs with overlapping canopies, posed a challenge for the software’s capacity to differentiate trees As a result, tree densities and diameters were overestimated, while tree heights were underestimated. Exploration of alternative algorithms and software is needed if measuring vegetation data on seismic lines with MLS is to be implemented.

Seismic lines, which are narrow linear clearings used for hydrocarbon exploration, have accumulated throughout Alberta’s forest landscapes for decades. The inconsistent natural recovery of seismic lines over time has led to a fragmented landscape and has incited the need for restoration programs and associated monitoring of forest recovery on seismic lines. In this study, we evaluated a technique where we used satellite imagery to visually assign recovery classifications based on whether the seismic line remained >50% visible (Not Recovered), <50% visible (Fractionally Recovered), or not visible (Recovered) in upland mixedwood forests. We ground validated the recovery classification on 22 seismic lines using the recovery criteria of 2000 stems ha⁻¹ and a mean tree height of 3 m. The categories of Recovered and Fractionally Recovered met the recovery criteria with 100% and 80% accuracy, respectively, while the Not Recovered category identified lines that failed to meet the recovery criteria with 83% accuracy. Based on these findings, visual interpretation of satellite imagery can be used to provide cursory-level recovery information for monitoring forest recovery on upland seismic lines at landscape-level scales.

Seismic lines are linear clearings created for oil and gas exploration. Regeneration on seismic lines in Alberta's boreal forest is limited by slow natural recovery, making them persistent features on the landscape and prompting interest in line restoration through vegetation reestablishment. The goal of this study was to establish an effective woody vegetation sampling method for monitoring seismic line regeneration in boreal mixedwood forests. Data collected in belt transects and circular plots were similar, and doubling the area sampled did not impact the results. Based on ease of implementation, a 30 m × 2 m belt transect in the center of a seismic line is the recommended sampling method. However, if woody understory vegetation is also being measured, dividing the belt transect into smaller areas is recommended as a single belt transect yielded less accurate height data than circular plots. Plots were also measured along seismic lines' edge and inner areas to determine if vegetation recovery differs across the width of the line. While all tree responses did not differ between the plot locations, woody understory vegetation was more abundant when measured along the inner seismic line locations. Therefore, if woody understory recovery is the focus of the sampling program, using plots placed across the seismic line width is recommended to prevent overestimation. These recommendations are intended for measuring woody vegetation recovery on 5 m wide seismic lines in upland mixedwood forests in the boreal forest; implementation in other environments or for other response variables requires additional testing.

Question: Understorey development is a great challenge in the restoration of many forest sites, particularly when sources of vegetation propagules are scarce. Can placement of propagule‐rich soil patches within reclaimed landscapes otherwise covered with propagule‐poor material promote the dispersal of vegetation from the patches into the surrounding areas?Location: Large reclamation site in the Canadian (Alberta) boreal forest.Method: Patches of propagule‐rich forest floor material were placed within a matrix of propagule‐poor peat material. Vegetation assessments (cover estimates, seed rain) were done surrounding these patches in the third and fourth growing seasons.Results: There was significant egress of species from the patches into the peat after four growing seasons, and overall species associated with the patches had higher cover in the peat than species that were associated with the peat itself. While wind‐dispersed herbaceous species from the patches were found at the leading edge of the egressing community, most species used vegetative propagation, resulting in short egress distances. Several patch‐associated species were found in seed rain collected on the peat areas but were not observed in this material, suggesting seedbed limitations.Conclusion: Despite the relatively short distance of egress, this experiment suggests that placement of propagule‐rich soil material within reclaimed landscapes will promote egress into adjacent propagule‐poor soil material.