Seasonal deposition of ferric hydroxide plaque on roots of wetland plants

Abstract

In three wetlands in southeastern Ontario, ferric hydroxide was deposited on the roots of Typha latifolia (maximum, 67 × 103 ppm); in four other wetlands, deposition was negligible (< 103 ppm). Iron deposition was seasonal, with the peak period in July–August corresponding to peak biomass production of shoots. In one wetland where Carex rostrata and Phragmites australis occurred, seasonal plaque formation was similar. Plaque formation was not obviously related to Eh and pH regimes.