Testate amoebae community structure in a hummock-lake bog in north taiga (Karelia, Russia)

In flat sphagnum quagmire in hummock-lake bog of northern taiga (outskirts of Chernaya River village, Louchi district, Karelia) 45 testate amoebae species was identified. Three community types were distinguished corresponding to different moisture content. In upper 0-3 cm sphagnum horizons in all community variants mixotrophic species Hyalosphenia papilio, Archerella flavum, Heleopera sphagni are predominate. In deeper horizons dominant species in communities are heterogeneous: in most wet biotopes hydrophilous species Difflugia spp, Arcella spp., Phryganella hemisphaerica prevail, in medium moist conditions Heleopera petricola, Hyalosphenia elegans, Nebela spp.. predominate. Since June to August abundance of Archerella flavum is increased, whereas Hyalosphenia papilio decreased. Maximal abundance (114800 ind. per gram absolute dry sphagnum) develops in wet Sphagnum fuscum biotope, minimal one (5400 ind. per gram) - in submerged Sphagnum majus at the edge of quagmire.