Volunteer Revegetation of Waste Rock Surfaces at the Bingham Canyon Mine, Utah

Abstract

Voluntary recolonization of sulfide-bearing waste rock dumps by native vegetation is inhibited by the harsh chemical and physical conditions. The success of volunteer vegetation on the waste rock surfaces at the Bingham Canyon (Utah) porphyry copper deposit is most strongly dependent on the soil pH and salinity, and to a lesser extent on physical characteristics such as compaction and distance from seed source. Vegetation cover and richness both decline below a paste pH of about 6 and above a paste conductivity of about 0.7 dS/m (for a 1:1 soil to water mixture). No significant vegetation establishment occurs below a soil pH of about 4.5. Young sulfide-bearing waste rock surfaces at Bingham Canyon have high salinity, but as reactive pyrite is depleted and salts are flushed from the soil, the salinity eventually declines, allowing volunteer native vegetation to become established on surfaces with a circumneutral pH. Under natural conditions, the pH of older acidic weathered surfaces will recover very slowly, but it can be rapidly raised by adding relatively small amounts of limestone because there are few intact reactive sulfides. For uncompacted waste rock surfaces with favorable chemical conditions, less than 90% gravel content, and that are located near a native seed source, the arithmetic mean volunteer vegetation cover was 56 +/- 24% and the mean species richness was 17 +/- 5. These data indicate that with adequate surface preparation and limestone addition, direct planting of older, acidic, but low salinity waste rock surfaces can greatly accelerate natural revegetation.

Use of hydrophilic polymers from diapers to aid the establishment of Spergularia purpurea in a mine soil

“…Vegetation can protect the soil from structural degradation that encourages surface run-off, and take up water further decreasing run-off and the risk of leaching of both beneficial and toxic elements. The application of amendments becomes necessary for the development of a plant cover [9]. If the establishment of native species could be promoted, they could stabilize areas that remain bare.…”

Improving Soil Fertility to Support Grass–Legume Revegetation on Lignite Mine Spoils

“…The average yield values were 3.1 and 2.4 times greater than those treated with NPK + magnesium limestone, especially during the early growth and establishment of the plots (July and September). It is important to underline the significance of gradually incorporating nutrients from the compost or some other organic amendments into the soil, if compared to NPK mineral fertilizers (Borden and Black 2005;Larney and Angers 2012;Leirós et al 1998;Nada et al 2011;Pedrol et al 2010). Even so, a loss of fertility was found in November with limiting values of P and CECe, although the limitation was less in the plots amended with compost.…”

Low levels organic amendments improve fertility and plant cover on non-acid generating gold mine tailings

“…The tailings left by the Gunnar mine were characterized as having levels of soluble salts sufficient to negatively affect plant cover like many other mine wastes (Borden and Black, 2005;Borden and Black, 2005). In similarly composed substrate (sandy texture with low organic matter content), Feagley et al (1994) attributed the low overall soluble salt content to the well-drained structure with little capacity to bind available ions.…”