A currently emerging issue in the western US is mine tailings. In Arizona alone there are 300,000 acres of tailings that contain a variety of toxic metals including arsenic, lead, and cadmium. In arid and semi-arid portions of the western US spreading of these metal toxicants occurs through a combination of wind and water erosion resulting in measured elevated levels in ecosystems, that are even significant distances from the tailings site.
UA SBRP Associate Director and Environmental Microbiologist, Raina Maier and her research team having been working on UA SBRP project “Phytostabilization of Mine Tailings in the Southwestern United States: Plant-Soil-Microbe Interactions and Metal Speciation Dynamics”. Promising preliminary results combined with the UA SBRP Research Translation Core’s communication with the Bureau of Land Management (BLM) (Translation Efforts Beyond the Laboratory: UA SBRP goes 1 - 1 with Local Citizens), has led to a $25,000 grant from the BLM to phytostablize a 1.5 acre mine tailings site adjacent to the San Pedro River in the San Pedro River National Conservation Area in southern Arizona. A mixture of native forb and grass seeds will be applied to establish a vegetative cover on 1.5 acres at the San Pedro River mine tailings site. The site will be monitored for two years following seeding to measure growth and to determine shoot metal uptake in selected plants.
This grant follows a preliminary 18-month revegatation trial supported by the UA SBRP to evaluate the growth of a salt and drought-tolerant plant species, fourwing saltbush (Atriplex canescens). The results of this initial trial indicated that saltbush could be established on the site without addition of organic matter or fertilizer amendments. For the single plant studied, metal uptake into shoot tissues did not exceed recommended guidelines with the exception of lead.The UA SBRP Research Translation Core is excited that this grant is the result of our ongoing communication with BLM and local community members. It is part of the Research Translation Core mission to build capacity within the community, while simultaneously maximizing its research efforts and leveraging additional funds and demonstration sites.