Soluble calcium and sulphate excesses related to stress in Pinus contorta on peat amendments of reclaimed landscapes in the boreal oil sands region.

A 13-year-old stand of Pinus contorta (lodgepole pine) showed various symptoms and degrees of nutrient deficiency on a reclaimed tailings sand dyke at the Suncor oil sands project in Alberta, Canada. The poorest growth occurred on soil from a deep mesic peat deposit underlain by marl, intermediate growth was observed on a peat-mineral mix of shallow, fibric origin and the best growth was on soil of moist upland forest floor origin with a cover of moss and litter fill. Soil samples were analysed for salinity and soluble cations, reaction and available nutrients in autumn 2005 and soil moisture profiles to 160 cm were determined during the 2006 growing season. The results showed a negative relationship between pine performance and increasing Ca and available sulphate-S, with the relationships stronger than indicators typically linked to poor peat amendment quality. Ca and SO4 were the main contributors to electrical conductivity and were also associated with elevated CaCO3(eq). The presence of elevated carbonates in some amendments contributed to high resistance to acidification of the upper soil profile by leaching, and alkaline reclamation soil may be detrimental to pine growth in relation to P availability.
A 13-year-old stand of Pinus contorta (lodgepole pine) showed various symptoms and degrees of nutrient deficiency on a reclaimed tailings sand dyke at the Suncor oil sands project in Alberta, Canada. The poorest growth occurred on soil from a deep mesic peat deposit underlain by marl, intermediate growth was observed on a peat-mineral mix of shallow, fibric origin and the best growth was on soil of moist upland forest floor origin with a cover of moss and litter fill. Soil samples were analysed for salinity and soluble cations, reaction and available nutrients in autumn 2005 and soil moisture profiles to 160 cm were determined during the 2006 growing season. The results showed a negative relationship between pine performance and increasing Ca and available sulphate-S, with the relationships stronger than indicators typically linked to poor peat amendment quality. Ca and SO4 were the main contributors to electrical conductivity and were also associated with elevated CaCO3(eq). The presence of elevated carbonates in some amendments contributed to high resistance to acidification of the upper soil profile by leaching, and alkaline reclamation soil may be detrimental to pine growth in relation to P availability.