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Problems posed by the protection of lamprey and fish localities of European importance in the drainage areas of the Dyje, Morava, and Odra rivers
Lusk, Stanislav ; Lusková, Věra ; Lojkásek, B. ; Halačka, Karel
In consequence of the accepted legislation concerning the protection of lamprey and fish species of European importance, potential sites of community interest (pSCI) have been selected for such species. At present, the national list of the proposed pSCI is being examined by the European Commission. If approved upon, the pSCI will be proclaimed "special areas of conservation" within the NATURA 2000 system. Although such pSCI and their populations are protected by legislation, there occur risks that endanger, both directly and indirectly, the quality of the pSCI and the population of the particular species. The examples mentioned in the paper indicate that such risks include local emergency pollution, construction of weirs and small hydraulic power plants, extraction of sediments from streambeds, cruising vessels, and stream modification. Such risks are due to the inconsequence and reluctance in observing the legal protection measures by concrete authorities of nature conservation.
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Biodiversity of standing floodplain waters and processes of its formation and preservation
Pithart, David
Water chemistry and planktic communities in the naturally eutrophic alluvial waters in the Lužnice floodplain have been studied. The floofplain waters are naturally eutrophic, with strong vertical physico-chemical gradients and oxygen depletions at the botom. Small pools and backwaters of this type have unique phytoplankton structure. Prevailing dominance of flegellates, namely Cryptophyceae, and low proportion of green chlorococcal algae and Diatoms, and almost absence of Cyanophyceae are very unusual for such eutrophic waters. Flagellate dominate thanks their ability to keep the vertical position in a permanently light limited conditions (resulted from poorly mixed water columns and intensive shading of water surface by vegetation). Floodplain geodiversity play crucial role, determining morphology and location of pools and backwaters, their exposition to flooding and inflows of underground water. Terrestial vegetation effects light exposition, leaf litter.
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