Selenium uptake by diverse plant taxa to assess bioavailibility in phosphatic shale. (S11-mackowiak707092-poster)
Authors:
C.L. Mackowiak* - USDA Forest Service
M.C. Amacher - USDA Forest Service-RMRS, Logan, UT
Abstract:
As part of the characterization of vegetation growing on shale waste rock from the phosphate mining operations of southeast Idaho, plant taxa representing forbs, legumes, grasses, and shrubs, as well as taxa associated with wetlands were grown in two greenhouse pot studies using 111 mg kg-1 Se phosphatic shale mine waste rock. Above ground biomass was clipped at the end of the growing season. Legumes contained the greatest amount of Se (over 70 mg kg-1) in oven-dried tissue, while shrubs and wetland species contained the least (less than 35 mg kg-1 Se). Selenium concentrations ranged from less than 4 mg kg-1 for Salix lasiandra (Benth.) to over 180 mg kg-1 for Lupinus
argenteus (Pursh.). Since the wetland species were grown under saturated (reduced) soil conditions, it is likely that Se bioavailability was less in these treatments. Legumes have a higher sulfur demand and Se being an analog, may partially explain the higher Se uptake by legumes. Additionally, the shale waste rock contains elevated amounts of other soluble trace elements, such as Cd, Mo, Ni, and Zn. Willows accumulated Cd and Zn, while legumes accumulated Ni and Mo. In order to protect grazing and browsing ungulates, legumes should not be used in revegetation programs and wetland willows may potentially pose a Cd and Zn hazard.
Speaker Information: Cheryl Mackowiak, USDA Forest Service, 860 N. 1200 E., Logan, UT 84321;
Phone: 435-755-3568; E-mail: [email protected]
Session Information: Tuesday, November 4, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 1609) Keywords: selenium; plant; phosphatic shale; bioavailable