Grant: Alliance Grants

Low-grade ore/large tonnage mine sites generate large tailings storage facilities that require ecological restoration after mine closure. The main objective of this project is to increase the expertise in the ecological restoration of metalliferous tailings storage facilities in a boreal forest context. More specifically, this project will address the generalized shortage of topsoil needed to create appropriate conditions for afforestation of mineral substrates at low-grade ore mine sites. First, it will explore how sporadic revegetation through isolated plantings on topsoil patches could contribute to reduce the quantity of topsoil required for restoration and facilitate afforestation on tailings storage facilities. New remote sensing tools will be developed to study the progress towards reference forests, including plant composition and vertical structure at the site scale. Second, it will investigate topsoil substitutes obtained by mixing ramial chipped wood, a new source of organic material for mine site afforestation in accordance with circular economy principles, with overburden soils. For both axes, advanced genomic analyses will be used to characterize the change in soil biodiversity associated with the tested revegetation techniques. Moreover, the sequestration of CO2 in soils will be quantified to assess the capacity of afforested mine sites to act as nature-based solutions for climate change mitigation. The proposed project will contribute to improve afforestation and biodiversity on active and legacy mine sites through the development of innovative tools for the monitoring of revegetated tailings storage facilities at the whole site scale, the evaluation of new revegetation techniques, and the use of appropriate knowledge transfer methods. Partners with complementary expertise (researchers, government and industrial mine managers, providers of phytotechnology services) are involved in the project to co-design concrete applications in ecological restoration. Finally, this project will train seven personnel in ecological restoration research, who will contribute to the design and implementation of sustainable revegetation practices on mine sites.