Abstract

Chile has many mine tailing deposits available for phytoremediation through the establishment of metal-tolerant plants. To guide such efforts, it is necessary to know whether roots exclude or take up metals, or if metals are mobilized to shoots. We evaluated a polyculture of ten native species 6 years after they were planted directly into tailings, amended with mycorrhiza before planting or planted with compost. All species were assessed for survival and hare damage. Growth, vigor, chlorophyll content index, and chlorophyll fluorescence were measured in seven species, and root and shoot concentrations of 11 metals and As were measured in five. All species had some level of stress, but there was no clear pattern related to foliar metal concentrations or amendments, the latter also having little effect on growth or survival. Copper, Fe, and Mo concentrations exceeded threshold toxicity levels for leaves and for animal feed in several species. Copper was most concentrated in the roots, and readily mobilized to leaves in three of the five species tested, but not in Prosopis chilensis (algarrobo) and Quillaja saponaria (quillay). Because of lower uptake overall, quillay is recommended for stabilizing tailings while also reducing transport to aerial tissues.

抽象的

智利有许多矿山尾矿床，可通过建立耐金属植物来进行植物修复。为了指导这些工作，有必要知道根系是否排除或吸收了金属，或者金属是否动员到嫩芽上。在将10种本地物种直接种植到尾矿中，在种植前或用堆肥进行菌根改良后的6年中，我们评估了10种本地物种的混养。对所有物种进行了生存和野兔危害评估。测定了7种植物的生长，活力，叶绿素含量指数和叶绿素荧光，并测定了5种植物中11种金属和砷的根和芽浓度。所有物种都有一定程度的胁迫，但没有与叶面金属浓度或修饰物相关的清晰模式，后者对生长或存活的影响也很小。铜，铁，钼的含量超过了几种物种的叶片和动物饲料的毒性极限水平。铜最集中在根中，并且在五个受测物种中的三个中很容易动员到叶上，但是在铜中却没有。智利Prosopis chilensis（阿尔加罗沃）和Quillaja saponaria（奎尔莱）。由于总体摄入量较低，建议使用奎莱胶来稳定尾矿，同时还可以减少运输到空中组织的速度。