Bio-intrusion barrier made of plants with allelopathic effects to improve long term perfomance of cover with capillary barrier effects

矿山废弃物中的硫化物矿物氧化产生的酸性矿山废水（AMD）无疑是采矿业中较为严重的环境问题。为了避免AMD的产生，可以建造具有毛细屏障效应（CCBE）的覆盖物，以限制下面的酸产生的矿山废物的氧气可用性。即使CCBE的业绩在短期内已在实地得到证明，但其长期效率仍有待证明。可能影响CCBE长期性能的因素之一是生物入侵，更具体地说是树根。本研究旨在评估具化感作用之植物所制成之生物入侵障壁，对限制树根入侵所造成之CCBE长期恶化之能力。化感作用是指一种植物对另一种植物的发芽和生长的抑制作用。为了达到项目目标，将在120个试验地块（3米x 3米）内繁殖三种具有化感作用的植物物种：蓝关节芦苇草、绵羊月桂和沼泽拉布拉多茶。将在实验地块中种植颤白杨、香脂杨、黑云杉、斑点桤木和杨柳（被确定为LTA CCBE长期稳定性最有问题的物种）的两年期幼苗。将采用不同的方法来评估具有化感作用的植物对目标树木的影响：树木形态特征的演变、根系结构、植物组织、土壤和水的化学分析。与此同时，将评估具有AE的植物对CCBE水收支的影响，以查看植物是否影响限制氧迁移的性能。最后，该项目将回答一些基本的生物学问题，关于化感化合物和根特性的相互作用，以及开发一个实用的方法来设计生物入侵屏障的CCBE。

Acid mine drainage (AMD) resulting from oxidation of sulphide minerals contained in mine wastes is undoubtedly the more serious environmental problem of the mining industry. To avoid AMD generation, covers with capillary barrier effects (CCBE) can be built to limit oxygen availability for the underlying acid generating mine waste. Even if the performance of CCBEs has been demonstrated in the field over the short-term, the long-term efficiency still has to be proven. One of the factors that could affect the long-term performance of CCBE is bio-intrusion, more specifically tree roots. This project aims at evaluating the capacity of bio-intrusion barrier made of plants with allelopathic effects to limit long term deterioration of CCBE caused by tree-root invasion. Allelopathic effects (AE) can be defined as the inhibition of germination and growth of a certain species of plant, by the use of another. To reach the project objectives, three plant species with allelopathic effects: Bluejoint reedgrass, sheep laurel and bog Labrador tea will be propagated within 120 experimental plots (3m x 3m). Two-year seedlings of trembling aspen, balsam poplar, black spruce, speckled alder and willow (identified as the most problematic species for the long term stability of the LTA CCBE) will be planted in the experimental plots. Different approaches will be used to evaluate the impact of plants with allelopathic effects on the targeted trees: the evolution of morphological characteristics of the trees, roots architecture, chemical analysis of plant tissue, soil and water. In parallel, the influence of the plants with AE on the CCBE water budget will be evaluated to see if the plants affect the performance to limit oxygen migration. At the end, the proposed project will give answers to some fundamental biological questions about allelopathic compounds and root properties interactions, as well as developing a practical approach for the design of bio-intrusion barriers on CCBE.