The diversity of organisms in aquatic environment
Members of the Hydrobiology Group studied topics concerning aquatic invertebrates, focussed on Mollusca, Oligochaeta, Hirudinea, Crustacea (Amphipoda, Cladocera, Copepoda, Harpacticoida), Ephemeroptera, Plecoptera and Diptera.
- Biodiversity and systematics of aquatic invertebrates
Streams on the territory of the Moravian Karst, Drahany Highlands, Czech-Moravian Highlands, Jeseníky Mts. and the Dyje and Ploučnice Rivers were sampled. The occurrence of selected target species was verified. Streams with little or no impact were preferably considered. The actual occurrence of amphipods Gammarus fossarum, G. roeseli and Dikerogammarus villosus was charted. Actual occurrence of Gammarus pulex in the Czech Republic was not confirmed, though some past authors mentioned this species from streams in Šumava and Krušné Hory Mts.
Based on long-term research of the biodiversity of mayflies (Ephemeroptera), which was carried out in 1950-1970 and 1990-2000 in all catchment areas of the Czech Republic, distribution maps of all species recorded so far were constructed. In total, nearly 2000 localities were studied which were distributed proportionally and covered all elevational zones and habitat types. The maps for 99 species of the order Ephemeroptera, including 3 extinct species, were constructed.
Mapping of the rare and endangered species of Plecoptera (Capnopsis schilleri, Leuctra geniculata, Isoptena serricornis, Agnetina elengatula etc.) was finished in 2004 and the respective publications are under preparation at present.
The results were included into the Fauna Europaea project (http://www.faunaeur.org), supported by the European Commission within the Fifth Framework Programme.
- The analysis of freshwater macrozoobenthos diversity with respect to habitat variables conditioned geographically
This research project was studied in connection with our participation at two projects of the Fifth Framework EU programmes, AQEM and STAR. The main goal was to demonstrate general principles of the macrozoobenthos community development. New biotic classification of streams (20 groups) was developed, based on a data set consisting of 300 reference localities, including both small and large streams. Environmental variables important for the invertebrate community composition were defined and selected, preferably such not influenced by natural variability (geographic longitude and latitude, distance from source, altitude, stream slope and stream order according to Strahler).
- The life and feeding strategies of stream meio- and macroinvertebrates in different stream types and under various conditions
Current conditions (slope of reach), bottom substrate and its permeability, altitude, distance from source i.e. in short, the ecological type of reach, determines the populations and communities of stream-bed organisms. Their life strategies must be adapted to frequent changes in running stream reach during the hydrological year and vegetation season. Generally, these processes are explained by the patch dynamic concept theory. Populations and communities, their traits and strategies in using available space and food supplies (energy budgets) could be defined by abiotic factors or environment and the patches.
The goals of the project were to clarify life strategies of target species (populations) regarded as bioindicators of defined stream zones from permanent stream fauna (oligochaetes and copepods), and from temporal fauna (mayflies, stoneflies and caddisflies). The results will be employed for the creation of models of stream environment status bioindication according to species and population traits and strategies in Central European streams.
- Environmental profiles of selected macrozoobenthos representatives in running waters of the Czech Republic
This research is coupled to the previous one, but its goal is aimed at practical purposes. Critical studies were elaborated concerning the saprobic evaluation, general methods of ecological stream status assessment and the choise of water quality indicators.
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