Epiphytic diatoms in lotic and lentic waters - diversity and representation of species complexes

Small streams and shallow ponds represent sensitive ecosystems and attached diatoms can serve as integrative indicator with fast response to environmental changes. Development of methods for ecological monitoring throughout Europe and their calibration for particular ecoregions are not finished yet and databases need to be filled by data from undersampled regions and overlooked substrates. The present study aims to explore the diversity of epiphytic diatoms in unexplored catchment areas with special attention to substrate specificity and distribution of unresolved diatom species complexes. Significant differences were found in diversity of both regions and water types (lotic/lentic). No significant differences were found in the case of substrates. CCA analysis showed significant influence of pH, water streaming (streaming/stagnant) and Lemna substrate to species composition. Surprisingly species complexes represent the majority of epiphytic assemblages with no significant differences between lotic and lentic waters or substrates except of Lemna. The high representation of complexes does not lead automatically to reduction of overall diversity of the sample.