Effects of non-segregated tailings on growth of oil sands reclamation plants

由于恶劣的气候条件和严重的土地干扰，油砂矿区的土地复垦具有极大的挑战性。油砂开采产生了大量的尾矿，必须回收利用。这些尾矿通常含有较高水平的化合物，可能会对植物造成伤害。油砂公司已经开发出不同的方法，以将尾矿对回收厂的影响降至最低。加拿大自然资源有限公司开发了一项技术，将浓缩剂与二氧化碳结合使用来固结尾矿，并生产钠含量较低的非分离尾矿(NST)。然而，关于油砂尾矿的化学成分如何影响用于这种尾矿材料的北方植物物种的生长和功能的现有知识有限。本项目将对NST尾矿的化学和物理特性进行表征，并将研究尾矿化学对油砂复垦场地常见植物种类生长和生理过程的影响。该项目还将调查植物对潜在有毒微量元素的吸收，以及尾矿对与植物根部相关的有益真菌的影响。这项研究的主要总体目标是产生所需的知识，以便为受NST尾矿影响的地区的复垦制定最佳战略。这项研究的具体目标是：i)表征NST尾矿对植物的影响和潜在毒性，ii)确定不同植物物种对NST影响地点的复垦的适宜性，iii)深入了解NST尾矿对植物的作用模式，以及iv)检查选定的复垦植物中菌根联合的益处。该项目包括七项研究，将在未来四年内在受控条件下的生长室中进行。研究结果将用于提高受油砂尾矿影响地区的植被恢复成功率。

Land reclamation of oil sands mining areas is highly challenging due to the harsh climatic conditions and the severity of land disturbance. Oil sands mining produces large volumes of tailings, which must be reclaimed. These tailings have commonly elevated levels of compounds that are potentially injurious to plants. Oil sands companies have developed different approaches to minimize the effects of tailings on reclamation plants. Canadian Natural Resources Limited has developed technology that uses thickeners in combination with carbon dioxide to consolidate tailings and produce the non-segregated tailings (NST) with lower sodium content. However, the existing knowledge of how the chemical composition of oil sands tailings affects growth and function of boreal plant species that are used for this tailings material is limited. The present project will characterize the chemical and physical properties of NST tailings and will examine the effects of tailings chemistry on growth and physiological processes in different plant species that are commonly planted in the oil sands reclamation sites. The project will also investigate the uptake of potentially toxic trace elements by plants and the effects of tailings on beneficial fungi associated with plant roots. The main general objective of the study is to generate knowledge that is required to develop optimal strategies for the reclamation of areas affected by the NST tailings. The specific objectives of the study are to i) characterize the effects and potential toxicity of NST tailings on plants, ii) determine the suitability of different plant species for the reclamation of sites affected by NST , iii) develop thorough understanding of the mode of action of NST tailings on plants, and iv) examine the benefits of mycorrhizal associations in selected reclamation plants. The project consists of seven studies that will be carried out over the next four years in growth rooms under controlled conditions. The results of the study will be used to improve revegetation success of the areas affected by the oil sands tailings.