Metalliferous soils

Metalliferous soils can occur naturally as in ultramafic (serpentine) or calamine soils, or they may result from human action. In both cases, the presence of Trace Elements (TE)s may be undesirable because of their potential toxicity to plant and animal life. Alternatively, the soil and/or its underlying strata may represent a potential source for the commercial extraction of these TEs

Metalliferous soils may be barren, support a characteristic flora, or be undistinguishable from non-metalliferous soils with respect to the vegetation. Plants growing on metalliferous soils have elevated concentrations of TEs in their shoots, thus providing an exposure pathway for TEs to enter the food-chain. Many hyperaccumulator plants occur exclusively on metalliferous soils

The extent and type of vegetation on metalliferous soils has important implications for the environmental risk of the site. Barren sites are prone to erosion and leaching. Metalliferous sites with vegetation that is undistinguishable from non-metalliferous sites may be inadvertently used for food production.

We investigate the plant-soil interactions on metalliferous soils with a view to finding out useful species for the phytomanagement of contaminated sites, or species that biomonitor of soil pollution. Such species provide information on soil quality that direct soil analyses do not reveal.

Ultramafic (serpentine) vegetation. The contact between ultamafic and calcareous soils, Dun Mountain, New Zealand. The Nothofagus forest (left) is unable to colonise ultramafic soil that contains high concentrations of Ni, Cr, Co, Mn, and Mg. Here the ultramafic flora is dominated by Chionochloa pallens, Hebe odora, Cassinia vauvilliersii, Dracophyllum uniflorum, Gentiana corymbifera, Phormium colensoi and Melicytus alpina.
Arabidopsis halleri. Arabidopsis halleri(formerly Cardaminopsis halleri ) colonising metalliferous soils near the town of Auby, Northern France. The abundance of this Zn hyperaccumulator is not surprising, given that the soil contains 2% zinc and 1% lead.

Publications related to metalliferous soils

Conesa HM, Robinson BH, Schulin R, Nowack B (2007). Growth of Lygeum spartum in acid mine tailings: response of plants developed from seedlings, rhizomes and at field conditions. Environmental  Pollution. 145, 700-707.

Madejón P, Marañón T, Murillo JM, Robinson BH (2006). In defence of plants as biomonitors of soil quality. Environmental Pollution 143, 1-3.

Moreno FN, Anderson CWN, Stewart RB, Robinson BH (2005). Mercury volatilisation and phytoextraction from base-metal mine tailings. Environmental Pollution 136(2), 341-352.

Madejón P, Marañón T, Murillo JM, Robinson BH (2004). White poplar (Populus alba) as a biomonitor of trace elements in contaminated riparian forests. Environmental Pollution 132, 145-155.

Moreno FN, Anderson CWN, Stewart RB, Robinson BH (2004). Phytoremediation of mercury-contaminated mine tailings by induced plant-mercury accumulation. Environmental Practice 6, 57-67.

Robinson BH, Russell C, Hedley MJ, Clothier BE (2001). Cadmium adsorption by rhizobacteria: implications for New Zealand pastureland. Agriculture, Ecosystems and Environment 87(3), 315–321.

Asensi A, Bennett FA, Brooks RR, Robinson BH, Stewart RB (1999). Copper uptake studies on Erica andevalensis, a metal-tolerant plant from southwestern Spain. Communications in Soil Science and Plant Analysis 30(11&12), 1615-1624.

Robinson BH, Brooks RR, Gregg PEH, Kirkman JH (1999). The nickel phytoextraction potential of some ultramafic soils as determined by sequential extraction. Geoderma 87, 293-304.

Chiarucci A, Robinson BH, Bonini I, Petit D, Brooks RR, de Dominics V (1998). Vegetation of Tuscan ultramafic soils in relation to edaphic and physical factors. Folia Geobotanica et Phytotaxonomica 33, 113-131.

Robinson BH, Brooks RR, Kirkman JH, Gregg PEH, Varela Alvarez H (1997). Edaphic influences on a New Zealand ultramafic (“serpentine”) flora: a statistical approach. Plant and Soil 188, 11 – 20.

Robinson BH, Brooks RR, Kirkman JH, Gregg PEH, Gremigni P (1996). Plant-available elements in soils and their influence on the vegetation over ultramafic (“serpentine”) rocks in New Zealand. Journal of the Royal Society of New Zealand 26 (4). 457-468.

Robinson BH (1997). The phytoextraction of heavy metals from metalliferous soils. PhD thesis. Massey University, New Zealand.