Carbon and nitrogen fluxes in reconstructed oil sands soils

位于艾伯塔省东北部麦克默里堡附近的阿萨巴斯卡油砂，估计蕴藏着1.3万亿桶沥青。大约10%的矿床足够浅，可以进行露天开采。在露天采矿之后，开垦涉及使用在干扰之前抢救的有机和矿物材料重建土壤。制定策略以最大限度地利用重建土壤中的养分资源是成功开垦的关键。特别是，通过调节整个养分模式，重建植物和重建土壤之间的生物地球化学循环是立地生产力的核心组成部分。这项研究将表征油砂地区具有代表性的复垦实践场地的土壤碳和氮通量。这些将与火灾后恢复的地点进行比较，火灾是艾伯塔省北部森林的主要自然干扰。在特定的实验室条件下，将碳和氮通量与土壤微生物群落联系起来，将为了解这些土壤中的养分有效性提供一个基线。田间实验将检验不同凋落物材料为土壤微生物、土壤动物和植物吸收提供养分的就地能力。最后，将结果进行整合，以便为这些重建土壤建立碳和氮通量的机理模型。总之，这里提出的研究将提供可测量的碳和氮通量与基本土壤过程之间的定量关系，这将有助于为油砂地区的可持续围垦制定更好的指导方针。

The Athabasca Oil sands located near Fort McMurray, in northeastern Alberta, contain an estimated 1.3 trillion barrels of bitumen. Approximately 10% of this deposit is shallow enough to be surface mined. Following surface mining, reclamation involves soil reconstruction using organic and mineral materials salvaged prior to disturbance. Devising strategies to maximize nutrient resources in the reconstructed soils is key to successful reclamation. In particular, the re-establishement of biogeochemical cycling between plants and reconstructed soils is a central component of site productivity through its regulation on overall nutrient patterns. This research will characterize soil carbon and nitrogen fluxes at sites representative of reclamation practices in the Oil sands area. These will be compared to sites recovering following fire, the main natural disturbance for Alberta's boreal forests. Linking carbon and nitrogen fluxes to soil microbial communities in defined laboratory conditions will provide a baseline for understanding nutrient availability in these soils. Field experiments will examine the in situ ability of different litter materials to supply nutrients for soil microorganisms, soil fauna, and plant uptake. Finally, results will be integrated so that a mechanistic model of carbon and nitrogen fluxes can be developed for these reconstructed soils. Comprehensively, the research proposed here will provide quantitative relationships between measurable carbon and nitrogen fluxes and fundamental soil processes that will help develop better guidelines for the sustainable reclamation of the Oil sands region.