Sezónní preference mikrohabitatu u vybraných řádů makrozoobentosu na řece Ostravici

Abstract

The thesis deals with the seasonal microhabual preferences given by selected orders of macrozoobenthos, especially orders of the water insects Ephemeroptera, Plecoptera and Trichoptera, in the Ostravice river. Four of its locations were selected: Staré Hamry (1), Frýdlant nad Ostravicí (2), above the mouth of Morávka (3) and Frýdek-Lískovec (4). Macrozoobenthos was harvested in typical river habitats: mostly on stones, on gravel and in moss, if found on the site. The individuals were taken from the benthic net, from the top, bottom and sides of the stones, from their dead zone and from the gravel or moss. Altogether, 720 individuals were removed from these locations. The work deals with the frequency of selected macrozoobenthos orders in selected microhabitats due to selected environmental variables (oxygen, temperature, pH, conductivity, ORP and current velocity). With the exception of pH, taxa always depended on more variables. Taxa showed a close dependence on temperature, pH and flow, ORP and oxygen, and also on pH and temperature, oxygen and flow. The dependence on conductivity and ORP was less pronounced.