Native Plant Restoration of Copper Mine Tailings: I. Substrate Effect on Growth and Nutritional Status in a Greenhouse Study

Abstract

Copper mine tailings are difficult to revegetate using native plants unless amendments are added to reduce acidity, decrease metal solubility, and improve nutrient availability. In this study, the effects of two amendments were tested for their ability to improve growth and survival of two native plant species growing in copper mine tailings. Unamended tailings from an abandoned copper mine in Washington State were compared with native soil, sandy gravel from local glacial outwash, tailings with a 15‐cm sandy gravel cap, and biosolids with sandy gravel over tailings. Two native plants, Sitka alder [Alnus viridis subsp. sinuata (Regel) A. Love & D. Love] and pearly everlasting [Anaphalis margaritacea (L.) Benth. & Hook. f.], were grown in a greenhouse for 3 to 4 mo in pots of each substrate. Plant biomass was determined and elemental composition of plant tissues were compared among substrates. Survival of both species was 100% in all treatments, but biomass production varied greatly among treatments, with the highest growth in the biosolids and gravel amendment and lowest growth in unamended tailings. Nutrient content varied by species and substrate with high AI concentrations in Sitka alder. Results suggest that N availability is most limiting to pearly everlasting and P is most limiting to Sitka alder. Use of biosolids in conjunction with gravel appears to be an effective tailings amendment.

Riparian Shrub Metal Concentrations and Growth in Amended Fluvial Mine Tailings

“…Copper accumulation in roots has been observed for birch (Gussarsson et al 1995;Kelly et al 1979;Utriainen et al 1997), alder (Kramer et al 2000), and willow (Punshon and Dickinson 1997;Rosselli et al 2003;Stoltz and Greger 2002;Vervaeke et al 2003). Our belowground Cu concentration results for thinleaf alder, water birch, and all four willows (Table 3) were consistent with previously reported plant Cu immobility.…”

“…Silver birch and downy birch have been shown to accumulate greater aboveground Pb concentrations (Margui et al 2007;Pahlsson 1989;Utriainen et al 1997) (Kramer et al 2000). Gaulke et al (2006) grew red alder in biosolids with a Zn concentration similar to our tailings and reported aboveground Zn concentrations similar to those we detected in thinleaf alder.…”

Phytoremediation of mine tailings in temperate and arid environments

“…& Hook. F. (pearly everlasting, Asteraceae), both demonstrated adequate plant biomass and shoot tissue exclusion of high concentrations of Al and Zn when grown in copper mine tailings located in Washington, US (Kramer et al 2000). In this study, a surface cover of 15 cm of gravel amended with a biosolids-woodchip mixture was applied to the tailings prior to planting.…”

Actinorhizal Alder Phytostabilization Alters Microbial Community Dynamics in Gold Mine Waste Rock from Northern Quebec: A Greenhouse Study

“…The successful application of Alnus rugosa in the revegetation of the Gays River lead-zinc mine tailings in Nova Scotia, Canada was first demonstrated in 1988 [ 10 ]. In more recent studies, alders have demonstrated an impressive ability to restore disturbed lands ranging from metal mine overburden, waste rock and tailings to oil sands tailings, while positively impacting soil fertility and increasing soil total nitrogen and carbon [ 11 – 23 ] Frankia inoculation prior to transplantation into mine residues has been shown to be beneficial to the growth and establishment of alders in mine residues [ 9 , 16 ; 24 – 25 ]. Actinorhizal alders were also successfully grown in tailings sand and composite tailings, where they positively impacted the diversity and activity of the indigenous soil microbial populations [ 13 ].…”