Native and Dryland Pasture Seed Mixes Impact Revegetation 12 Years after Pipeline Construction in Southern Alberta

Abstract

Activities associated with agriculture, grazing, and the energy industry have altered large tracts of native rangeland in North America. Pipelining causes intense local disturbance by removal of vegetation and alterations to soil horizons. Following a disturbance, reclamation is required to return the land to equivalent land capability. Revegetation is usually by seeding native and/or agronomic (non-native, dominant) species. This study investigated the long-term effects of native and dryland pasture (91% non-native species) seed mixes, grazing, and right-of-way (RoW) treatments on revegetation of native rangeland in southeastern Alberta. Native seed mixes were more successful at enhancing seeded vegetation cover than dryland pasture seed mixes. Grazing had a significant impact only on the survival of non-native grasses. The seed mix did not significantly affect total, native, non-native, annual, or perennial forb cover. Total forb cover was significantly higher on the trench with the dryland pasture seed mix than all other RoW treatments (storage, work). This long-term study suggests that native seed mixes can result in successful revegetation of reclamation following pipeline construction.