Abundance and diversity of Gymnamoebae at varying soil sites in northeastern USA

Population densities, morphotypes, sizes and diversity of soil gymnamoebae were assessed at six different soil sites located at Torrey Cliff Nature Preserve and on the campus of the Lamont-Doherty Earth Observatory in Palisades, N.Y. Gymnamoebae were categorized into four morphotypes based on a previously published method. Only the pine grove and swampy soil contained populations of all four types of gymnamoebae. The mean densities (cells/g dry soil) were 1,182(pine grove soil), and 1,399 (swamp soil). Only type 4 gymnamoebae (flattened, discoidal) such as Platyamoeba and Vannella sp. were detected in the remaining four sites. These, however, were in large quantities, with mean densities ranging from 3,218 for the soil under the rock to 5,055 for soil containing gravel. Diversity indices varied from a high value of 3.7 in the swampy soil to 1.8 to 2.6 in other locations.