The structure and species richness of the diatom assemblages of the Western Carpathian spring fens along the gradient of mineral richness.

Species composition changes along the pH and calcium gradients within wetlands were frequently studied for different groups of organisms, but few data are available for algae. Here we list 188 diatom taxa collected as epibryon and epipelon at 13 spring fens in the Western Carpathians distributed along the gradient of mineral richness. Species richness decreased along the gradient from calcareous fens to mineral-poor Sphagnum-fens. In agreement with fen typology based on higher plants, bryophytes, and molluscs, the same four fen types were identified. For each spring-fen type indicator diatom species were suggested. Conductivity and pH appeared to be the most important environmental factors responsible for the variation in diatom species data.