Identifying Anthropogenic Soil Change in a Smelter-Affected Environment.

The Canadian Boreal Shield area surrounding Flin Flon, Manitoba and Creighton, Saskatchewan has suffered forest dieback due, in part, to anthropogenic disturbances related to the local mining and smelting industry. These disturbances have included tree harvesting for fuel and lumber to support the mine and smelter operations and metal and acid deposition from smelter emissions. Since the late 1990s, limestone has been applied to soil in an attempt to re-vegetate barren landscapes; however only moderate success has been achieved. The inconsistent vegetation response to liming may be attributed to variations in soil organic matter (SOM) quality and overall soil nutrient status. In order to determine why vegetation growth is not consistent in all areas, two 3 km transects were established North and South of the smelting stack. Samples were taken at 0 – 5 cm and 5 – 15 cm increments every 100 m for the purpose of characterizing select physical, chemical and microbial SOM fractions. This includes measurement of dissolved organic carbon (C) and nitrogen (N), light and heavy fraction C and N and microbial biomass C and N. In addition, whole soil C, N, phosphorous (P) and sulfur (S) concentrations, pH, cation exchange capacity and particle size distribution will also be measured. Results will be summarized with respect to distance from the smelting stack and extent of vegetation growth (% ground cover and % woody cover). Findings will identify variations in the nutrient status of SOM and whole soils in the Flin Flon-Creighton area and help support the development of future eco-restoration and revegetation strategies.