Abstract

The objective of Project 30 was to select populations (i.e., ecotypes) from native, indigenous plant species that demonstrate superior growth characteristics and sustainability on acidic, heavy metals-contaminated soils occurring at varying elevations in western Montana. The native vegetative cover was required to meet the following criteria:

• Reduce potential risks to human and wildlife receptors following exposure to heavy metals via the routes of ingestion (plant, soil, and surface water) and inhalation (fugitive dust) for these contaminants
• Accelerate creation of improved wildlife habitat and aesthetic conditions on these historically degraded lands

The three project specific goals were to:

• Release seed of native species (indigenous to western Montana) that are valuable for the restoration/reclamation of hardrock mines, mill tailings, and smelter-affected sites
• Field test potential releases (of these species) at the Anaconda Smelter Superfund Site to verify adaptation to acidic/metals-rich soils and interspecies compatibility
• Provide technology transfer through the development of educational materials for the scientific community, seed producers, and reclamation specialists regarding new plant materials and establishment techniques

Local accession number 9081620 of slender wheatgrass met the quantitative criteria for canopy cover, aerial biomass production, and vigor when grown in pure stands; it also contributed significantly to the superior performance of mixed indigenous versus mixed commercial accessions used for reclamation in the Anaconda area. For the five trace elements evaluated, only the copper level in the 2005 sample exceeded the generally acceptable concentration for most livestock species (i.e., 47 milligrams per kilogram [mg/kg] versus 40 mg/kg), but not for wildlife (55 mg/kg). However, the concentrations of aluminum and copper (i.e., 151 and 15 mg/kg, respectively) in the 2006 tissue analyses imply plant surface contamination by soil particles influenced the results from 2005. Subsequently, Copperhead Selected class germplasm of the indigenous slender wheatgrass was released to commercial growers in the summer of 2006.

The above accession joins the following releases that were developed under the Development of Acid/Heavy Metal-Tolerant Cultivars project: Western Selected germplasm basin wildrye, Old Works Source Identified germplasm for fuzzy tongue penstemon, and Prospectors Selected germplasm for common snowberry. Local accessions of big bluegrass and bluebunch wheatgrass are expected to be released to commercial growers within the next two years.

Contact

Norma Lewis

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