Pine Reforestation Evaluation On Dyke 2W

This project was initiated in 2005 to understand why a stand of planted lodgepole pines displayed such variable growth rates across the slope of Pond 2/3 Dyke W on the Suncor Oil Sands Project site. Samples were taken of generic soil quality parameters of the peat-mineral mix capping material that the lodgepole seedlings were planted on in 1992. A follow-up study took place in 2011 in the original study area and several additional sites to sample: (1) soil parameters that may influence vegetation health, (2) pine foliar tissues to look for nutrient imbalances, and (3) mycorrhizae to determine if reclamation success is linked to variable rates of symbiotic fungi interactions with the planted pine.

The 2005 sampling suggested a link between soil parameters including EC, excess soluble calcium and available sulphate-S and lodgepole pine growth. The presence of elevated levels of calcium carbonate equivalence was considered a soil pH buffer, and it was suspected elevated pH levels were decreasing nutrient availability and inhibiting growth of lodgepole pine, which prefers acidic soils. These results were published in a paper in 2007. In the 2011 study, it was confirmed that characteristics of the mineral substrate in the peat-mineral mix in the original plot (Plot 1) were causing salinity that was negatively influencing the growth and that it would be difficult to remedy even with fertilization. In future, mineral substrates should be assessed before use in peat-mineral mixes in future, and marl lacustrine deposits, such as the one used, can be identified in the field and avoided. Pines at Plots 2 and 4 (with soil nutrients similar to natural conditions) were growing well. Pines at Plot 3 could use NPK fertilization, but effectiveness may be limited by high pH and free calcium. NPK fertilizer was also recommended for Plot 5 pines. High mycorrhizal colonization was found at all plots. More study is needed to determine if they are beneficial or parasitic and to compare fungal species found in natural stands to planted stands to see if they differ.