On functional attributes of testate amoebae in the succession of freshwater aufwuchs

The dynamics of testate amoebae in the Aufwuchs of a small stream (Ilm, Thuringia, Germany) was investigated over a two year period. Using experimental methods (exposure of artificial substrates) the specific performances of testate amoebae species during succession were assessed and described as functional attributes. The most important taxa were classified according to dispersal ability, preference for particular phases of succession, and ability to dominate the assemblages during late phases of succession. Comparison with previous work in standing water bodies showed both similarities and differences in the functional attributes of testate amoebae with regard to succession in the different aquatic environments. It was shown that some species have remarkably constant performance which might be used to indicate the successional status and dynamic characteristics of assemblages of testate amoebae in Aufwuchs.