Dyke 5 Fertilizer Research Plots

Suncor initiated the Dyke 5 Fertilizer Research Plot Study in 2004 to evaluate the effectiveness of fertilizer use for reclaiming and ultimately increasing rates of revegetating disturbed areas. The study was designed to compare the rate of coniferous and deciduous tree growth along with natural invading vegetation between fertilized and non fertilized treatment sites on reclaimed tailings sand. Plots were amended with Suncor’s standard muskeg soil material, seeded with barley, and planted with white spruce, trembling aspen, white birch and blueberry. Treatment sites were fertilized annually. The study ran from 2004 to 2008.

Spruce and aspen seedlings increased in height with no significant difference between treatments for either species by end of study. Seedling survival decreased for both species in both treatments with no significant difference between treatments by end of study. Fertilizer does not appear to have affected seeding growth or survival of either tree species. As expected for forb and graminoids, an increase was seen in first few years as they colonized, then a decline was noted. There was a significant difference (p <0.05) between forb and graminoid cover in treatments during the study. Shrub cover increased over time in both treatments with no significant difference between treatments. An initial increase in tree cover was observed in 2005 and 2006 for both treatments, followed by a decline in the next two years, and there was no significant difference between treatments. Total living cover plus total cover (vascular + litter) increased for the first two years, then declined, with a significant difference between treatments over the study period – plots treated with fertilizer showed a higher percent cover than non-fertilized plots, attributed to build-up of herbaceous vegetation (forbs and graminoids) and subsequent litter produced by these species.