Ecohydrological functioning of an upland undergoing reclamation on post‐mining landscape of the Athabasca oil sands region, Canada

TitleEcohydrological functioning of an upland undergoing reclamation on post‐mining landscape of the Athabasca oil sands region, Canada
Publication TypeJournal Article
Year of Publication2018
AuthorsGingras-Hill, T., F.C. Nwaishi, M.L. Macrae, J.S. Price, and R.M. Petrone
KeywordsAthabasca Oil Sands region, ecohydrology, forest floor material, hydrogeochemistry, peat–mineral mix, Reclamation, upland

Ecohydrological functioning of natural Boreal forest in Canada's Boreal Plains is a product ofinteractions between soil hydrophysical characteristics and hydrogeochemical processes. Theseinteractions create a moisturenutrient gradient within the surface soils, increasing alonglowrelief transitions from upland to riparian zone, and in turn influence the distribution of vege-tation communities. It is not yet known if/when analogous ecohydrological functions can beachieved in constructed uplands following industrial disturbance, such as that following oil sandsdevelopment. Hence, to assess this, we studied interactions between hydrogeochemicalprocesses and vegetation colonization in a constructed upland relative to hydrophysical proper-ties of 2 reclamation cover substrates during a typical continental climate's growing season.Our results indicated that in 3 years of postconstruction, the establishment of a moisturenutrientgradient that supports vegetation colonization along slope positions was still limited byheterogeneity of cover substrates. Portions of the upland under peatmineral mix werecharacterized by lower nutrient availability, high moisture content, and establishment of plantedshrubs and trees. In contrast, forest floor materials plots were characterized by poor soil quality,but higher nutrient availability and greater colonization of invasive grasses and native shrubs.We suggest that the colonization of underdeveloped soils by invasive grasses may facilitatepedogenic processes and thus should be accepted by reclamation managers as a successional mile-stone in the recovery of ecohydrological functioning of constructed uplands. Poor soil structureunder forest floor materials could not support edaphic conditions required by plants to efficientlyutilize fertilizer, making this practise futile at the early stage of soil developmen