Peatlands have persisted across the globe for millennia and function globally as long-term sinks of atmospheric Carbon

Peatland ecosystems play a critical role in global climate regulation, as such, their conservation, management, and restoration have been identified as a key activity to meet the UN Sustainable Development Goals, particularly during the current UN Decade of Ecosystem Restoration.

Mining and smelting operations have contaminated peatlands through the atmospheric deposition of pollutants released by industrial processes over many centuries. Sudbury, Ontario is one of the world’s largest metal mining centres, and historically has been the largest global point source of SO2 (sulfur dioxide) and metal particulate pollution. Subsequently, ecosystem reclamation has become a prominent goal of the regional community through the City of Greater Sudbury’s Regreening Program.

While regionally > 30,000 ha have been reforested (including liming of the landscape to decrease the acidity of the uplands), sequestering an estimated 500,000 Mg of C, there are ~6,000 ha of valley-bottom peatlands that are the densest current, and potential, C store in this landscape2. Yet, many of these peatlands are contaminated with decades of legacy industrial emissions from smelting resulting in degraded functionality and a loss of ~100 years of sequestered C. Notably the keystone Sphagnum “peat mosses” that drive net C sequestration and limits greenhouse gas (GHG) emissions cannot tolerate high levels of cationic elements (nickel, Ni; copper, Cu; or calcium/magnesium, Ca/Mg) or sulphur (S).

These peatlands, which are normally C-sequestering powerhouses are no longer operating as atmospheric C sinks in this contaminated landscape