Biochar affects aspen seedling growth and reclaimed soil properties in the Athabasca oil sands region

Restoring ecosystem function after oil sands surface mining involves reestablishing the biotic and abiotic ecosystem components which affect biogeochemical cycles and fluxes. In boreal forest ecosystems pyrogenic carbon is a native soil component that affects a variety of biogeochemical parameters and biochar is its human-made analog. To evaluate the benefits of biochar amendment to reclamation cover soils, we compared characteristics and function of peat mineral mix (PM) and forest floor mineral mix (FFM) with and without biochar in an 18 wk greenhouse study. We assessed nutrient bioavailability (NO3, NH4, P, K, S, Mg, Ca), foliar nutrient concentrations (N, P, K, S, Mg, Ca, Na, Mo), soil respiration, rhizosphere polysaccharide concentration, soil organic matter (SOM) stability, and Populus tremuloides Michx. seedling growth. Seedling growth increased significantly on PM cover soil with biochar. Biochar improved K nutritional status and potentially interacted with Na bioavailability in PM, affecting growth. Soil respiration significantly decreased in PM with biochar and increased in FFM. Soil organic matter stability was positively correlated with seedling growth and increased with biochar. Our findings suggest that biochar may have a significant positive effect on upland forest reclamation in the Athabasca Oil Sands Region, especially on sites that are reclaimed with PM.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author