Thirty years of revegetation experience at the Key Lake uranium mine in northern Saskatchewan

Abstract

The Key Lake Mine is located within the Athabasca Basin in northern Saskatchewan and has been active as a mining and/or milling operation since the early 1980s. The mine site will undergo significant reclamation activities over the next one to two decades. Surficial soil in the area is dominated by erodible, well-drained, outwash sand with low nutrient levels. The climate is cold and dry, meaning plants must be cold-hardy and drought-tolerant. Vegetation is also the primary means of erosion control. Re-establishing vegetation on reclaimed areas is challenging, but is also critical to the long term success of reclamation. Early efforts at revegetation focussed on replanting the climax vegetation (typically jack pine) directly to recreate the forest. The methodology evolved over time to combine seeding of grasses with tree planting; this was more successful, but was still not achieving the goal of regenerating the forest. Observations of the initial stages of natural succession on waste rock piles have suggested that revegetation should begin with pioneer species such as mosses, lichens and shrubs. Creating suitable micro-topography for the introduction and establishment of key pioneer species, and taking advantage of available sources of nutrients and soil amendments can propel the revegetation process onto a trajectory of ecological succession and natural reforestation. Recently, Cameco has adopted a multi-disciplinary approach to revegetation efforts. This paper provides a brief description of our efforts to take advantage of the available resources (local plants, soil amendments) to facilitate the revegetation process.