Carbon and nitrogen fluxes in reconstructed oil sands soils

阿萨巴斯卡油砂位于艾伯塔省东北部麦克默里堡附近，估计含有1.3万亿桶沥青。该矿床中约有10%的地层较浅，可以进行露天开采。在地表开采之后，复垦涉及到在扰动之前利用回收的有机和矿物材料进行土壤重建。制定策略，最大限度地利用重建土壤中的养分资源是复垦成功的关键。特别是，植物和重建土壤之间的生物地球化学循环的重建是通过其对整体养分模式的调节而成为场地生产力的核心组成部分。本研究将描述油砂地区具有代表性的复垦做法的土壤碳和氮通量。这些将与火灾后恢复的地点进行比较，火灾是阿尔伯塔北部森林的主要自然干扰。在确定的实验室条件下，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基线。田间试验将考察不同凋落物为土壤微生物、土壤动物和植物吸收提供养分的原位能力。最后，将结果整合起来，以便为这些重建土壤建立碳和氮通量的机制模型。综合而言，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开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.