| Author/Editor | Smolar, Nataša; Vrhovšek, Dani; Kosi, Gorazd | |
| Title | Effects of low flow on periphyton in three different types of streams in Slovenia | |
| Type | članek | |
| Source | In: Bretschko G, Helešic J, editors. Advances in river bottom ecology; 1996 Aug 27-30; Brno. Leiden: Backhuys publishers, | |
| Publication year | 1998 | |
| Volume | str. 107-15 | |
| Language | eng | |
| Abstract | Impact of abstraction of water on periphyton was assessed on three different types of streams: on the alpine stream Tržiška Bistrica and lowland stream Dravinja after abstraction of water for small hydroelectric power plants. Three sections have been chosen for each stream: the first reference section upstream the dam, the second section downstream the dam with reduced flow and the third section after water coming back into the stream. On the karst stream Branica three sections on different locations were chosen due to intergranular porosity of substrata. The samples of periphyton were collected during summer and winter minimum flow in the period 1993-1996. At the same time, the stream flow and the current velocity were measured. The qualitative samples of periphyton algae were collected as well as quantitative samples of periphyton for the evaluationof dry mass (DM), ash-free dry mass (AFDM) and chlorophyll a (chl a). The influence of the reduced flow on periphyton community in the section TB2 of the stream Tržiška Bistrica was observed, namely in changed species composition of periphyton, changed biomass, species deficit and in decreased average current velocity at TB2. A small abstraction of water from the stream Dravinja did not have an influence on periphyton composition. There were more differences within sections, than among sestions. There were different conditions for periphyton composition present on a very short section of the stream Branica. Sections B1 and B2 were more similar in periphyton community in comparison with the section B3, where there was very low flow and in summer almost no current velocity. | |
| Descriptors | FRESH WATER ALGAE CHLOROPHYLL BIOMASS |