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干扰，开采油砂后的土地开垦工作具有挑战性。在许多垦区，土壤含盐量高，pH值高。由于土壤水分含量低、大气水汽压差大以及种植后的胁迫，植物遭受干旱条件的影响。由于缺乏对影响开垦地植物生长和存活的一些基本过程的了解，特别是森林林下植物的生长和存活，这一问题更加严重。杜鹃花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。它们在复垦场地的生长受到土壤因素的严重影响。这一科的植物需要一种特殊类型的环状菌根组合，以增强它们对开垦地不利土壤因素的抵抗力。因此，在本项目中，我们将研究埃里克菌根在赋予茜草科植物高pH、高盐度和抗旱性方面的作用，以及参与这些植物反应的过程。这项研究的主要长期目标是对埃里克类菌根真菌侵染的艾美耳科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垦区的旱地和低地蓝莓、拉布拉多茶和越橘植物根际中的ericid菌根；ii)研究ericid菌根组合是否提高了这三种茜草科植物对高pH、干旱和盐分的耐受性；iii)确定ericid菌根协会和pH对旱地和低地蓝莓水分关系的影响以及植物和真菌水孔蛋白在这些反应中的作用；以及iv)研究在油砂垦区种植后菌根植物的生长反应。该项目包括几项研究，这些研究将在受控条件下的生长室和实地进行。这项研究的结果将被用来改善油砂区的绿色植物恢复。

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.