Pyrogenic Carbon Is a Legacy Substrate in Wildfire Ecosystems Such As the Boreal Plains: Should It be Used in Land Reclamation?.

Pyrogenic carbon (PyC) is a substrate legacy that is ubiquitous in pyrogenic ecosystems. It has the ability to absorb organic molecules as well as cations and anions, thus altering the chemical environment of soil and changing what is available to plants and microorganisms. PyC has the potential to be used as a soil amendment in the land reclamation of surface mined sites in the Athabasca oil sands region. Determining the effect of different types of PyC on reclamation soil processes, namely C and nitrogen (N) mineralization, and microbial community structure through sequencing will determine if it is beneficial to re-creating ecosystem function. PyC from three different sources (wildfire, pyrolysis, and coke) was applied to 3 different soil types (forest soil after fire, peat-mineral mix, and forest floor mineral mix) at a rate of 5% by weight in triplicate. All three soils had the highest rate of C mineralization when in the presence of wildfire-PyC suggesting that it aided in creating a more suitable environment to the microorganisms in these soils, or possibly by inoculating the soils better  than did coke-PyC, or pyrolysis-PyC. Coke-PyC produced the lowest C mineralization, but did improve microbial activity in the peat-mineral mix suggesting that it might improve the quality of this substrate. N availability followed a similar trend as C. It was interesting to note that Pyrolisis-PyC caused a significant shift in microbial succession in the natural forest soil and the forest floor minreral mix, but not the peat mineral mix. Field trials are needed to determine if PyC can improve soil-plant-microbe interactions in a multi-species environment and decrease the time to certification.