Oil sands mining in Alberta, Canada has disturbed large areas of peatlands, the dominant regional ecosystem type, yet no formal strategies exist to reconstruct the landscape or its vegetation. Peatland reclamation is difficult, but approaches are now being tested to determine the feasibility of rebuilding these ecosystems. In compliance with a new provincial regulatory framework, a pilot reclamation fen and associated watershed was constructed in an oil sands mine near Fort McMurray, Alberta. In a large-scale multifactorial field experiment, revegetation efforts tested introducing bryophyte and vascular plants by moss layer transfer, seeds, and greenhouse grown seedlings under wood-strand mulch and with a Typha latifolia weeding treatment.
Results/Conclusions
Four years after planting, the moss layer transfer with Juncus balticus seedlings treatment was most effective at maintaining fen bryophyte and vascular plant cover and richness. Weeding did reduce T. latifolia percent cover but was not necessary were fen vascular plants were introduced due to competitive exclusion. The most successful fen vascular species to establish was Carex aquatilis, which rapidly colonized the fen but reduced cover and richness of other desirable fen plants. Depth to water table also influenced species distribution, with shallow water tables supporting more T. latifolia and lower bryophyte and vascular plant richness and cover. Overall, our research demonstrates that it is possible to establish fen bryophyte and vascular species and limit T. latifolia invasion in a constructed fen. To prioritize plant diversity and bryophyte establishment, future projects should design for greater water table heterogeneity, select fen species tolerant of expected abiotic conditions, and introduce co-dominant vascular plants as seedlings. This research is the first of its kind to evaluate a range of revegetation strategies for fen reclamation. We assert that it is possible to restore fen peatlands in the post-mining landscape of Alberta, and that despite the constraints, a range of successful outcomes are achievable.