A Multi-disciplinary Approach to Reclamation Research in the Oil Sands Region of Canada

A 7-year research project into the long-term performance of reclaimed landscapes on saline-sodic overburden from oil sands mining in north-central Canada has demonstrated the importance of a multi-disciplinary approach. The land capability assessment tool used by the industry evaluates three key areas: available soil moisture, salt impact, and biological response (including nutrients). Detailed field monitoring and sampling demonstrated the relative performance of three different layered covers (35, 50 and 100 cm) and one monolayer cover ( 100 cm) through the tracking of water content, suction. stored water volumes, interflow/runoff and water availability for plant growth. Salt ingress into the cover from the underlying waste and salt release through interflow flushing has also been monitored. This long-term monitoring has provided physically based measurements of cover performance that clearly highlight the inability of thin (35 cm) or monolayer covers for providing sufficient moisture to meet all demands throughout a growing season. Interpretation of this data has also provided key insights into the mechanisms governing cover performance. This physically based evaluation was supported by direct measurements of tree development and tree ecophysiology. Vegetation indicators included plant species composition and abundance, tree growth rates, foliar nutrient contents, and plant ecophysiology.