Relationship between plant biodiversity and heavy metal bioavailability in grasslands overlying an abandoned mine

Abandoned metal mines in the Sierra de Guadarrama, Madrid, Spain, are often located in areas of high ecological value. This is true of an abandoned barium mine situated in the heart of a bird sanctuary. Today the area sustains grasslands, interspersed with oakwood formations of Quercus ilex and heywood scrub (Retama sphaerocarpa L.), used by cattle, sheep and wild animals. Our study was designed to establish a relationship between the plant...