diatom, fen, conductivity
Analysis of water samples from 10 fens in NE Iowa, collected 13-14 November 1987, revealed a gradient from acid, low conductivity water conditions (pH 5.6, alkalinity 30 mg/I HCO, conductivity 65 μmho, total hardness 30 mg/I Ca) to circumneutral, moderately conductive conditions (pH 7 .2, alkalinity 390 mg/I, conductivity 705 μmho, total hardness 380 mg/I Ca). Three sites along this gradient were sampled 15 May 1988 and 3 September 1988 to evaluate seasonal variation in water conditions. Examination of composite diatom samples collected concurrently with the water samples yielded 150 taxa, of which 14 are new Iowa distributional records and 6 remain unidentified. Previous investigators have reported 102 of these taxa from other Iowa fens, bogs, or prairie swales. Only 58 have been reported from the Cedar River basin, where most of these fens are located. This evidence suggests these scattered small wetlands resemble similar areas some distance away more than the surrounding surface waters. Distributional patterns of diatoms along the environmental gradient appear sufficiently distinct to permit delineation of species autecology.
Journal of the Iowa Academy of Science
© Copyright 1992 by the Iowa Academy of Science, Inc.
Main, Stephen P. and Busch, David E.
"Diatoms of Northeastern Iowa Fens,"
Journal of the Iowa Academy of Science: JIAS: Vol. 99:
, Article 5.
Available at: http://scholarworks.uni.edu/jias/vol99/iss1/5