Role of ericoid mycorrhizas in establishment of ericaceous plants in oil sands reclamation areas

由于恶劣的气候条件和严重的土地扰动，油砂开采后的土地复垦工作具有挑战性。在许多垦区，土壤含盐量高、ph值高。由于土壤含水量低、大气蒸汽压亏缺高和种植后胁迫，植物遭受干旱。由于缺乏对影响填海地点植物生长和生存的一些基本过程的知识，特别是对森林下层植物的知识，这个问题更加严重。埃里卡科植物在北方森林中发挥着重要的生态作用，对原住民具有特殊的文化意义。它们在填海造地的生长受到土壤因素的严重影响。本科植物需要一种特殊类型的菌根组合来增强其对开垦场地不利土壤因素的抵抗力。因此，在本项目中，我们将研究ericoid菌根关联在赋予ericica植物高pH、高盐度和抗旱性中的作用，以及这些植物响应所涉及的过程。该研究的主要长期目标是为埃里卡类菌根真菌定殖的埃里卡属植物的生理过程提供新的知识。具体目标是：1)鉴定天然林地和油砂复垦区旱地和低地蓝莓、拉布拉多茶和越橘植物根际的ericoid菌根；2)检验ericoid菌根结合是否增强了这三种ericoid植物的高pH值、耐旱和耐盐性；iii)确定原生菌根结合体和pH值对旱地和低地蓝莓水分关系的影响，以及植物和真菌水通道蛋白在这些响应中的作用；iv)研究油砂复垦区种植后菌根植物的生长响应。该项目包括几项研究，这些研究将在受控条件下的生长室内和实地进行。研究结果将用于改善油砂区种植白垩系植物的植被恢复。

Land reclamation efforts following oil sands mining are challenging due to the harsh climatic conditions and the severity of land disturbance. In many reclamation areas, soil contains elevated salinity and high pH. Plants suffer from drought conditions due to low soil moisture content, high atmospheric vapor pressure deficit and post-planting stress. The problem is aggravated by the lack of knowledge concerning some of the fundamental processes that affect plant growth and survival in reclamation sites, especially for the forest understory plants. Plants of the Ericaceae family play important ecological roles in the boreal forests and are of special cultural importance to the First Nations people. Their growth in reclamation sites is severely impacted by the soil factors. Plants of this family require a specific type of ericoid mycorrhizal associations to enhance their resistance to unfavorable soil factors in reclamation sites. Therefore, in the present project, we will examine the role of ericoid mycorrhizal associations in conferring high pH, salinity, and drought resistance to ericaceous plants and the processes involved in these plant responses. The main long-term objective of the proposed study is to contribute new knowledge concerning the physiological processes in ericaceous plants colonized by the ericoid mycorrhizal fungi. Specific objectives are to i) identify the ericoid mycorrhizas in the rhizosphere of upland and lowland blueberry, Labrador tea and lingonberry plants in natural forest sites and in oil sands reclamation areas, ii) examine whether ericoid mycorrhizal associations enhance high pH, drought and salinity tolerance in these three ericaceous plant species, iii) determine the effects of ericoid mycorrhizal associations and pH on water relations of upland and lowland blueberries and the role of plant and fungal aquaporins in these responses, and iv) examine the growth responses of mycorrhizal plants following planting in oil sands reclamation areas. The project consists of several studies which will be carried out in growth rooms under controlled conditions and in the field. The results of the study will be used to improve revegetation of oil sands areas with ericaceous plants.