Root development is important to ensure tree survival in conditions of water stress. Despite their long-recognized role, little attention has been given to their development on waste rock slopes subject to rapid drainage. This study was conducted in an open-pit gold mine in a boreal forest. Its main objective was to establish a plantation design with a moderate level of competition for water resources on a waste rock slope. A hybrid poplar plantation was established in May 2013 on a soil-covered waste rock slope of 33%. The experimental design included three different poplar spacings: 1 × 1 m, 2 × 2 m without herbaceous seeding, 2 × 2 m with herbaceous seeding and 4 × 4 m. The poplars responded to increased competition resulting from closer spacing and herbaceous seeding by investing less energy in diameter and height growth. Poplar individuals that were subject to high levels of competition were able to acclimatize to water stress conditions by increasing root length density and specific root length and by reducing above-ground biomass. This study indicates that some clones of hybrid poplar showing phenotypic plasticity in the ratio of above- and belowground growth can be adapted for short-term revegetation of mine sites.

根系发育对于确保树木在缺水条件下的生存至关重要。尽管它们的作用早已得到认可，但在排水迅速的subject石山坡上的开发却很少受到关注。这项研究是在北方森林的露天金矿中进行的。其主要目的是建立一个在废石坡上对水资源竞争程度适中的人工林设计。2013年5月在土壤覆盖的waste石坡度为33％的地方建立了一个杂交杨树人工林。实验设计包括三种不同的杨树间距：1×1 m，无草本播种的2×2 m，有草本播种的2×2 m和4×4 m。杨树对较小的间距和草本植物播种导致的竞争加剧作出了反应，为此在直径和高度增长上投入较少的能量。经受高水平竞争的杨树个体能够通过增加根长密度和比根长并减少地上生物量来适应水分胁迫条件。这项研究表明，一些杂种杨的无性系表现出表型可塑性，其地上生长和地下生长的比例可以适应矿区的短期植被恢复。