Differences in the Distribution of Some Bog Diatoms: A Cluster Analysis

Abstract

Differences in the distribution of diatoms inhabiting the floating mat at Mud Lake Bog, Williams County, Ohio [USA], were examined using a cluster analysis. Mat samples were collected on a biweekly basis from June-Nov. 1977 at the 3 selected study sites. Of the 56 diatom species identified from these samples, 36 were used in subsequent data analysis. The distribution of diatoms on the Mud Lake mat may be site-related. Four distinct assemblages, or clusters, of diatom species were evident: the Carex, Scirpus, Sphagnum-Larix and Carex/Sphagnum-Larix assemblages. Multiple regression analysis was used to relate these differences in distribution to certain physical and chemical parameters, e.g., temperature and levels of PO4, NO2, NO3, pH and Ca. The differences in diatom community composition from site to site on the Mud Lake mat are attributed primarily to variations in the levels of pH and Ca among the 3 distinct sampling sites.