Long-Term Effects of Copper Mine Tailings on Surrounding Soils and Sclerophyllous Vegetation in Central Chile

Abstract

This study analyzed the nutrients and metals concentrations of the surrounding soils and sclerophyllous vegetation of a tailing at the CODELCO–El Teniente copper mine in Central Chile. The content of metal, macro-, and micronutrients were analyzed in the soils outward from the tailing till 60-m distance at depths of 30, 60, and 90 cm, and in the foliage and stems of the native vegetation associated to the tailing. At plant level, we measured height, diameter, level of damage, and physiological attributes. Cu, Ni, Cr, and As were higher in the tailing, whereas soil Mn and Fe were higher at 60 m from the tailing. Soil K was higher at 30-cm depth, whereas Na was higher at 90-cm depth. Foliar Cu was higher in Acacia caven (40.5 mg kg−1), whereas the levels of Cu and Zn in stems were higher in Quillaja saponaria (6.5 mg kg−1 for Cu and 13.1 mg kg−1 for Zn). As the values of water potential and quantum efficiency of the photosystem II averaged − 1.1 MPa and 0.73, respectively, these two species exhibited no physiological stress. Only Q. saponaria tended to increase the level of damage at higher distances from the tailing. A. caven and Q. saponaria exhibited foliar contents of Cu and Fe considered toxic (Cu from 18.5 to 40.5 and Fe from 298 to 407 mg kg−1); however, both species were able to prosper at the limit of the tailing.