English

Abstract

The ecology of Typha-dominated marshes at the Tar Creek Superfund Site, northeast Oklahoma, was evaluated during the summers of 2000 and 2001. Since 1979, unabated discharges of contaminated mine water (pH 5.9, alkalinity 414 mg/L as CaCO3, 170 mg Fe/L, 11 mg Zn/L) into a former pasture has led to the development of an extensive volunteer wetland. Study sites included the impacted marsh receiving mine drainage (East Marsh) and an adjacent reference site receiving storm water (West Marsh). Vegetation sampling transects and quadrats were established and monitored for percent cover, species richness, and growth metrics. Above- and below-ground biomass, culm lengths, and culm densities were determined. Ash free dry weight, organic matter content, and Fe, Zn, Pb, and Cd concentrations were measured in roots, stems, leaves, and inflorescences. Percent cover ranged from 75-95%, and although dominated by Typha spp., 11 different species of vegetation were identified in East Marsh. In 2001, West Marsh was co-dominated by Scirpus spp. West Marsh demonstrated the highest total biomass with belowground biomass consistently higher than aboveground biomass. Culm densities in West Marsh were lower than East Marsh, and in 2000, cumulative stem lengths were directly related to densities. Ash free dry weights showed the highest amounts of inorganic matter in roots and lower amounts in above ground foliage. Concentrations of Fe and Zn were greatest in roots, but were also greater than background levels in stems, leaves, and flowers. Vegetation in West Marsh was metal-impacted, most likely due to back flow of mine water during low flow conditions. Variability in ecological metrics for the two summers is likely due to climatic differences (especially precipitation) between years.