Forest species in the recovery of soils contaminated with copper due to mining activities

Mining is the most important economic activity in Chile; causing significant degradation of the environment in the arid regions. The Coquimbo Region has suffered serious soil and water pollution because of heavy metals from mining, particularly copper. Implementation of measures that help to minimize the environmental impact of mining tailings requires knowledge about the adaptability of vegetal species to degraded soil conditions. Our objective was to determine and compare the phytostabilization abilities of native and exotic shrub species in areas extremely damaged by mining activities in the Coquimbo Region. The survival growth, and canopy development rates of 20 species were evaluated by two experiments. The Cu quantity in stems and leaves and at three soil depths was measured. Our results indicated that Acacia saligna is the best species in accumulating heavy metals (average of 34.8 ppm in leaves and 12.3 ppm in stems, both for non-fertilized soils), while demonstrating average survival rates over 80 %. This study concludes that A. saligna is the best species for phytostabilization activities in mine tailings of the Coquimbo Region.