Early Ecosystem Genesis Using LFH And Peat Cover Soils In Athabasca Oil Sands Reclamation

Abstract

Peat mineral soil mix has been the predominant cover soil used in Athabasca oil sands reclamation. Use of LFH mineral soil mix (forest litter layers and underlying mineral soil) has recently been mandated by regulatory approvals. Effectiveness of these cover soil types to provide diverse, native plant communities long term was compared at four research sites four to thirteen years of age. LFH mineral soil mix produced significantly greater woody plant density, vascular plant species richness, native species richness, total cover and native species cover; peat mineral soil mix had significantly higher non-native (weed) species cover. Species composition, growth form assemblage and dominant species differed between cover soils. LFH mineral soil mix is a superior cover soil to peat mineral soil mix for native plant community development. Patches of bare soil on both cover soils had significantly different soil chemical and physical properties than soil at patches of diverse vegetation.