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

Abstract: Differences in the distributions of diatoms inhabiting the floating mat at Mud Lake Bog, Williams Co., Ohio, were examined using a cluster analysis. Mat samples were collected on a biweekly basis from June to November 1977 at the three selected study sites. Thirty-six of the 56 diatom species identified from these samples were used in subsequent data analysis. The results of the clustering program clearly indicated that the distribution of diatoms on the Mud Lake mat is site-related. Four distinct assemblages, or clusters, of diatom species were evident: the Carex, Scirpus, SphagnumLarix and Carex/Sphagnum-Larix assemblages. Multiple regression analysis was used to relate these differences in distribution to certain physical and chemical parameters, such as temperature, and levels of P04, N02, N03, pH and calcium. 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 calcium among the three distinct sampling sites.