Beckett, P, Lavigne, J, Basiliko, N, Spiers, G, Hebert, M, Baudet, O & McCaffrey, T 2025, 'Are newly available soil amendments helpful to the 50 years of practices in 
restoring woody landscapes in Sudbury, Ontario, Canada?', in S Knutsson, AB Fourie & M Tibbett (eds), Mine Closure 2025: Proceedings of the 18th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1-7, https://doi.org/10.36487/ACG_repo/2515_100
(https://papers.acg.uwa.edu.au/p/2515_100_Beckett/)
Abstract: Sudbury has been a producer of base metals, especially nickel and copper, for over 140 years. Decades of atmospheric sulphur and metal pollution resulted in a sparse plant cover and stunted trees that led to severe erosion and degradation of forest soils. However, since the 1970s, pollution controls and the outstanding Sudbury Regreening Program have rehabilitated 25,000 ha of impacted landscape. Increasingly, the program is focusing on restoring native biodiversity (utilising 75 native trees and shrubs) and introducing understory species. A diversity of lichens and mosses has also returned to the developing forests and soil microbe communities are re-establishing. Estimates of forest carbon stocks in the regreened upland landscapes of Sudbury since 1978 show about 0.67 M tonnes of sequestered carbon or the equivalent of ca. 10 years of fossil fuel carbon emissions from the region. Other soil amendments as potential replacements for the limestone and fertilisers currently used in the Regreening Program are under investigation in short-term experiments. These included residuals from pulp and paper mills (wastewater treatment biosolids, biomass boiler ash) and municipal wastewater treatment biosolids, all showing some potential benefits. Overall, the landscape around Sudbury has greatly changed in the past 50 years enough that no more intervention is needed in some areas. The landscape changes have given a new image of the city and provided opportunities for recreation and other outdoor activities. There is a current effort to restore some of the damaged peatlands within the city.

Keywords: rehabilitation, biodiversity, smelter damage, nickel, copper, soil amendments