Distribution of epipelic diatoms in artificial fishponds along environmental and spatial gradients

Abstract

Although epipelic diatoms play a key role in primary production of many ecosystems, many aspects of their biodiversity, ecology and geographical distribution are poorly understood. The present study is based on sampling of 45 man-made fishponds in the Czech Republic covering an environmental gradient from oligo/dystrophic highland ponds within protected areas to the eutrophic/hypertrophic lowland ponds used for intensive fish production. Diatom distribution patterns assessed using biomass and species composition variables were assessed along environmental and geographical gradients. In total, 185 epipelic diatom taxa were found in the investigated samples. The differences in species composition between sites were correlated with environmental parameters, but not with the geographic distance of the localities. This pattern might suggest that niche-based control, rather than the effect of dispersal limitation, is the main driving force in the species composition of epipelic diatoms in fishponds. The alpha-diversity of sites correlated with altitude, nitrogen and chlorophyll a concentrations but did not correlate with the area of the ponds. The significant relationships between local abundance of species and their regional occupancy were very similar to previous studies of diatoms in boreal streams. In addition, these data concur with patterns known for multicellular organisms suggesting that in this respect diatoms may not differ from groups of organisms with larger body sizes.

IS TEMPORAL OCCURRENCE OF DIATOMS RELATED TO SPECIES TRAITS, LOCAL ABUNDANCE, AND REGIONAL DISTRIBUTION?1

“…This result is well in line with some early ideas on rescue effects on populations in patchy habitats (Brown and Kodric‐Brown 1977). We emphasize though that the local abundance and regional distribution were positively related in these data (see also, Soininen and Heino 2005, Poulíčková et al. 2009).…”

Environmental and spatial controls of biotic assemblages in a discrete semi-terrestrial habitat: comparison of organisms with different dispersal abilities sampled in the same plots

“…All bryophyte species forming at least small tufts were collected across the plot, including bryophytes growing in water as well as those forming small hummocks, and were washed and squeezed into sampling bottles. Captured diatoms were cleaned with a mixture of concentrated sulphuric and nitric acids and mounted in Naphrax for detailed identification to species level as described by Poulíčková et al. (2009); 400 individuals from each sample were counted.…”

Morphological and molecular study of epipelic filamentous genera Phormidium, Microcoleus and Geitlerinema (Oscillatoriales, Cyanophyta/Cyanobacteria).

“…Although epipelic eukaryotic algae were previously studied, e.g. diatoms (reproductive biology, cryptic speciation, geographic biodiversity and bioindication; Poulíčková et al 2008aPoulíčková et al , 2008bPoulíčková et al , 2009, epipelic cyanobacteria have been largely overlooked. The ecology of epipelic cyanobacteria is poorly understood.…”