Oil sands surface mining in the Athabasca region of northern Alberta (Canada) is a significant anthropogenic disturbance that resets boreal forest development and succession to early stages. During surface mining, the vegetation is cleared, the topsoil is salvaged, and the overburden (the layer of sand and clay in between the topsoil and the oil sands) is piled (see Fig. 2 in Audet et al.1 for an explanation of the land-reclamation procedure). After mining is finished, the landforms (composed of overburden and tailings sand) are capped with organic matter-rich soil covers made of either upland-derived forest floor-mineral mix (FFMM) or a lowland-derived peat-mineral mix (PMM)2. Alberta’s oil sands deposits represent an economically viable proven reserve of about 166 billion barrels of crude bitumen covering 142,200 km2 of land in the boreal forest3. Among the three oil sands deposits in Alberta (Peace River, Cold Lake and Athabasca areas), surface mining is only possible in the Athabasca region. The surface mineable area represents a total of 4,750 km2, with 895 km2 of land already disturbed. Ecosystems affected by oil sands surface mining lose their ecological functions due to the disappearance of above- and below- ground species. It is, therefore, crucial to reclaim these areas using strategies that provide the best conditions for site recolonization in order to quickly reestablish a self-sustaining and functioning ecosystem. Reclamation is the process of recovering ecosystem services through revegetation but not necessarily with the original species.
Stefani, F., N. Isabel, M.-J. Morency, M. Lamothe, S. Nadeau, D. Lachance, E. H. Li, C. Greer, É. Yergeau, and B. D. Pinno. 2018. The impact of reconstructed soils following oil sands exploitation on aspen and its associated belowground microbiome. Scientific reports 8:2761.