Improving revegetation of oil sands reclamation sites with mycorrhizal ericaceous plants

由于杜鹃花科植物在恶劣的环境中依赖于杜鹃花科植物的菌根而难以在油砂复垦区建立。杜鹃花科植物在北方森林中具有重要的生态功能。因此，在油砂地区成功重建这些设施是油砂行业的优先填海项目之一。在早期的研究中，我们证明了一个共同的开垦实践涉及土壤堆存是有害的杜鹃花科植物。即使是一个相对较短的，一年，持续时间的储备导致了急剧下降的丰富性和多样性的根杜鹃花菌根（ERM）真菌影响植物的生长和生存。我们还表明，重新建立的杜鹃花科植物在油砂回收区是不可能成功的，没有适当类型的ERM真菌的存在。以前已经确定，高土壤pH值和频繁发生的干旱是影响复垦地植物生长的常见有害因素。拟议的项目通过开展受控环境和实地研究来解决这些问题，以调查可用于改善油砂复垦区杜鹃花科植物生存和生长的不同方法。该项目还旨在更好地了解植物-菌根相互作用，提高高土壤pH值的耐受性和植物水分关系的ERM植物。拟议研究的主要长期目标是提供新的知识，可用于改善与ERM菌根植物的油砂地区reverteation。具体目标是：1）通过不同的ERM培养物培养根系，开发可用于提高堆填复垦土壤再植被潜力的方法; 2）研究堆填时间对ERM接种潜力和植物生长的影响; 3）确定各种ERM组合的pH耐受性;和4）检查有助于在用ERM真菌Pezoloma ericae和Meliniomyces variabilis定殖的蓝莓植物中增强抗旱性的过程。

Ericaceous plants have been difficult to establish in oil sands reclamation areas due to their dependence on ericoid mycorrhizal associations for survival in harsh environments. Ericaceous plants play important ecological roles in the boreal forests. Therefore, their successful re-establishment in oil sands areas is among the reclamation priorities for the oil sands industry. In an earlier study, we demonstrated that a common reclamation practice involving soil stockpiling is detrimental to ericaceous plants. Even a relatively short, one-year, duration of stockpiling resulted in a drastic decrease in the abundance and diversity of root ericoid mycorrhizal (ERM) fungi affecting plant growth and survival. We also showed that the re-establishment of ericaceous plants in oil sands reclaimed areas is not likely to be successful without the presence of appropriate types of ERM fungi. It has been previously established that high soil pH and frequent episodes of drought are common detrimental factors affecting plant growth in reclamation sites. The proposed project addresses these concerns by carrying out controlled-environment and field studies to investigate different approaches that could be used to improve survival and growth of ericaceous plants in oil sands reclamation areas. The project also aims at better understanding of the plant-mycorrhizal interactions that improve high soil pH tolerance and plant water relations in ERM plants. The principal long-term objective of the proposed study is to contribute new knowledge that can be used to improve the reveteation of oil sands areas with ERM mycorrhizal plants. Specific objectives are to: 1) Develop the methods that could be used to enhance revegetation potential of stockpiled reclamation soil by inoculating roots with different ERM cultures, 2) Examine the effects of stockpiling duration on ERM inoculation potential and growth of plants, 3) Determine pH tolerance of various ERM associations, and 4) Examine the processes contributing to enhanced drought resistance in blueberry plants colonized with the ERM fungi Pezoloma ericae and Meliniomyces variabilis.