Natural Revegetation Research

Reclamation in the Alberta Oil Sands Region has focused on capping disturbed areas with a salvaged peat-mineral mix substrate and planting trees, forbs and grasses to establish ground cover and prevent erosion. It has been proposed that natural recovery, which relies on the native soil propagule bank and propagule migration from surrounding areas, may facilitate revegetation and reclamation of the oil sands. To investigate this, Suncor initiated revegetation research on ~ 20 and 30 year old peat mineral storage dumps in 2007 at WA 5, WA 16 and Crane Lake that had vegetated naturally to forested sites. The ungroomed dumps with rough microtopography enable an investigation of natural revegetation and biodiversity on 1+ m thick reclamation material that did not receive fertilizing, seeding or transplants. Research objectives are to determine: (1) species composition of boreal forest vegetation on stockpile sites; (2) if there is a relationship between vascular species cover and composition and pH, electrical conductivity and texture of the substrate; (3) if there is a relationship between vascular species cover and composition and micro and macro topographic characteristics; (4) if there is a relationship between non-vascular species composition and macro topographic characteristics; and (5) the successional status of the vegetation on the study site.

Natural recovery of upland boreal forest vegetation on a lowland substrate is possible and a highly admixed peat-mineral substrate can support self sustaining and evolving plant communities. Current reclamation techniques require intense inputs such as equipment, plant propagules and human hours, which natural recovery could help reduce. It may also facilitate development of healthier ecosystem processes than traditionally reclaimed sites. It takes a long time to develop a suitable plant community, which may not suit developers and regulators, but should be considered a viable option, particularly as part of a progressive reclamation plan and in areas where a native plant community is desired for the end land use. Further on-site research suggestions: (1) characterizing micro/macrofauna and fungi as indicators of ecological success; (2) effect of CWD on community composition; (3) plant rooting depth in relation to substrate texture and soil profile restrictions; (4) soil layer development and peat decomposition; (5) soil water and community development in hummocks vs depressions; (6) soil nutrient trends in organic matter vs mineral soil and relation to community development; (7) resistance of naturally recovered plant communities to invasive species; and (8) successional development of communities as indicators of ecological success.