The Influence of Soil Amendments On Plant Growth and Microbial Community Structure In a Smelter-Affected Soil.

Hudson Bay Mining and Smelting Co., Limited (HBMS) has operated a metal mining and smelting complex in Flin Flon, Manitoba since the 1930s. Multiple disturbances,  including forest fire, tree harvesting for fuel and lumber, soil erosion, and metal and acid deposition from smelter emissions have all contributed to the loss of forest vegetation in the area. Although closure of the smelter in June 2010 has alleviated some revegetation pressure, predominant vegetation in the affected areas is composed of a non-native metal tolerant grass community. Efforts to revegetate the area with applications of lime have been moderately successful, but have not worked in all areas. This project tested five amendment combinations on limed soil for their influences on the growth of Vicia americana and Deschampsia cespitosa in a greenhouse setting. Preliminary results suggest that interactions between soil and treatments affect the growth and establishment of plant seedlings. Above and below-ground biomass was significantly affected by soil-treatment interactions. Since a healthy microbial community is essential for forest revegetation, the microbial community structure shifts resulting from these treatments will be assessed as well. Treatments that buffer plant growth and help build a healthy microbial community may be used in the field to revegetate the smelter-affected areas in the future.