Improving revegetation of oil sands reclamation sites with mycorrhizal ericaceous plants

在油砂复垦地区，由于在严酷的环境中依赖埃里克菌根协会生存，埃里克科植物很难建立起来。橡胶科植物在北方森林中起着重要的生态作用。因此，它们在油砂区的成功重建是油砂行业的优先复垦任务之一。在早些时候的一项研究中，我们证明了一种涉及土壤储备的常见围垦做法对芥科植物是有害的。即使是相对较短的一年储藏期，也会导致影响植物生长和存活的根埃里克样菌根(ERM)真菌的丰度和多样性急剧下降。我们还表明，如果没有合适类型的ERM真菌的存在，油砂开垦地区的埃里科植物的重建不太可能成功。以前已经确定，高土壤pH值和频繁的干旱是影响开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研究和实地研究来解决这些问题，以调查可用来改善油砂开垦地区芥菜类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，以改善ERM植物对高土壤pH的耐受性和植物水分关系。拟议研究的主要长期目标是提供可用于改善油砂地区ERM菌根植物复垦的新知识。具体目标是：1)开发可用于通过接种不同ERM培养物来提高堆积复垦土壤恢复潜力的方法，2)研究储存时间对ERM接种潜力和植物生长的影响，3)确定不同ERM组合的pH耐受性，以及4)研究有助于提高被ERM真菌Pezoloma ericae和Melinimyces varbilis定居的蓝莓植物抗旱性的过程。

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.