Phytostabilization of arsenic-rich gold mine tailings in the Victorian Goldfields, Australia. Water use by high value Eucalyptus trees: ecophysiological considerations

摘要

Field experiments investigated the establishment of dryland eucalypt species in arsenic-rich sulphidic gold mine tailings. Surface capping materials which comprised benign crushed waste rock amended with topsoil or biosolids, provided a substrate favourable to initial seedling growth. Cappings also allowed roots to penetrate into the tailings. Xylem water potential measurements of plant stems showed that midday water potential (Ψmd) for all species was similar for either summer or spring measurement. This indicates that the osmotic stress did not appear to greatly compound the drought stress in tolerant tree species. The use of stable isotopes of <'2> H and <'18> O are currently being undertaken to relate tree water isotopic composition and to compare it with rainwater in the upper cover profiles or tailings matrix water.