Edge effects of seismic footprint in the lowland boreal ecosystems of Alberta

Restoration success depends on recolonization by native biodiversity as much as on direct interventions (site prep, tree planting). Residual forests and peatlands bordering disturbed areas are reservoirs of biodiversity to recolonize sites undergoing reclamation and restoration. Seismic lines in particular may exert substantial edge effects on biodiversity. This project aims to gain a better understanding of edge effects on a range of taxa (plants, lichens, bryophytes, arthropods, soil fungi), and their variation by disturbance type, size, shape and orientation, to improve restoration planning and policies. Research will run from 2022 to 2024. Phase 1 – measuring extent, magnitude and nature of edge effects adjacent to seismic lines, in connection with the Boreal Ecosystem Recovery Assessment (BERA) project, measuring edge effects on plant functional traits and application of remote sensing; Phase 2 – assessing how edge effects change over time; and Phase 3 – assessing whether restoration treatments mitigate these edge effects and address interaction of time and treatment on edge effects. Ongoing field sites at Swan Hills (already established for earlier edge effect studies) will be used, and new field sites will be established at Clyde Lake, Christina Lake, Peace River, Kirby South, Swan Hills, and CHRP Area A.

No final report/conclusions; some preliminary findings from 2023. Bryophytes: (1) ~120 taxa (20 liverworts); (2) colonizer species most often found on mounds of treated lines; (3) microhabitat and microtopography important for diversity; pools and hollows more diverse than hummocks; (4) pools created by mounding deeper with fewer species than natural pools/hollows; (5) species composition different between line, edge and interior. Plant cover: Less trees on untreated vs treated lines, less medium shrubs on treated than untreated and fen, less creeping shrubs and more graminoids on lines than fen, less bryophytes on treated lines than untreated and fen. Soil moisture: higher on lines than fen, especially on untreated sites. Canopy cover: similar patterns of cover past edge, denser canopy cover near edges of untreated sites. Larch higher on edge and 7-12 m of treated sites, tree height lower on treated for larch and black spruce. Arthropods (Peace River only) – not much difference in species richness but composition may be different. Remote sensing data was found to be useful for tree height and density, microtopography and depth to water table and can complement ground data. Research in all areas continues. The project engaged and began collaborations with the local Indigenous community.