Restoration of foothills rough fescue grassland following pipeline disturbance in southwestern Alberta

Abstract

The effects of pipeline construction and reclamation techniques on the restoration of rough fescue plant communities following pipeline construction in southwestern Alberta, Canada were evaluated after 7-40 years. The pipeline construction right-of-way (ROW) sites varied from no recovery of rough fescue grassland to moderate recovery. The ROW sites had a higher proportion of introduced grasses and forbs, less topsoil, and poorer rangeland health than the adjacent undisturbed grassland. Within the ROW sites, less topsoil was present on those with larger diameter pipe and which had topsoil fully stripped from the ROW during construction. Introduced grasses, Festuca ovina (sheep fescue) and Poa compressa (Canada bluegrass), succeeded in establishment following seeding and persisted for at least 40 years. Poa pratensis (Kentucky bluegrass) dominated many of the ROW sites. Contributing factors to moderate recovery of rough fescue grassland were related to post-growing season pipeline construction, ideally, between August and March, summer or fall seeding, and minimum disturbance trench-only stripping. Reclamation practices appeared more important than time since restoration in the restoration of rough fescue grassland.