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Application of phytosociological survey and GPS mapping in assessment of the elimination effects of invasive neophytes in the Morávka catchment
Lacina, Jan
After disastrous flood in 1997, more distribution of invasive neophytes, particularly Reynoutria spp., was noticed in lower course of the River Morávka (including Special Area of Conservation The Morávka floodplain). The invasive neophytes expand both in flood-plain forest and on gravel bars, one of the last habitats for critically endangered species Myricaria germanica in the Czech Republic. Since 2006 the project „Rescue of floodplain habitats in the Morávka catchment” has been developed for maintaining and sustaining of autochthonous species, supported by European Union within the framework of Life Program. The mechanical and chemical combination of agents is used to eliminate the population of Reynoutria spp. This can negatively affect the occurrence of other species. The methods of phytosociological survey and GPS mapping is used to assess the efficiency of elimination action and its negative impacts.
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The ten-year development of vegetation cover of the Bečva river flood channel with special regard to ecotones
Lacina, Jan
During the disastrous flood in July 1997 the Bečva river created notable flood channels, which are considerably more complex and wider than the previous technically designed one. In the fall of the vegetation period in 1997 the six most interesting segments between towns Valašské Mežiříčí and Přerov were chosen and left in further natural development. During 10 years the processes of spontaneous succession have been examined by means of repeated phytosociological records on the investigative transects which have been located on various habitats. Dynamic development of river channel and its vegetation communities (from grassy-herbal heath to flood-plain forest and its ecotones) differentiated by hydrologic conditions, topography and grain-size distribution is very notable on the transect near Osek nad Bečvou. It is indisputable that the high-magnitude flood revitalizated the riverine landscape, diversified its character and contributed to the higher biodiverisity.
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Factors affecting the species composition of fish communities inhabiting sections of the rivers Morava, Dyje, Odra and Lužnice and their adjacent floodplains
Lusk, Stanislav ; Lusková, Věra ; Lojkásek, B. ; Hartvich, P.
The species composition of fish communities was studied in sections of the rivers Morava and Dyje (Black S. basin), Odra (Baltic S.), Lužnice (North S.) with floodplains. The following factors appear to determine the species composition of the ichthyofaunae inhabiting the hydrological regions: Sea basin, location of the section in the longitudinal profile of a stream, absence of migration barriers, presence of fishponds, fishery management. As regards the origin of a community, the pertinence to a basin is of greatest importance and migration from the lower sections. As regards the species richness of ichthyofauna, the region of confluence of the rivers Morava and Dyje is the richest of the whole Czech Republic - 38 native species, 9 of which occur only in that region, 7 alien species was recorded in that region. The region of the Odra R. was found to harbour 29 native and 4 non-native species; that of the Lužnice R., 25 native and 5 non-native fish species and 1 lamprey species .
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Large-scale rehabilitation in the alluvial area along the lower reaches of the Dyje River
Lusk, Stanislav ; Pražák, O. ; Lusková, Věra ; Halačka, Karel ; Vetešník, Lukáš
The Dyje River between Lednice and Bulhary was straightened, canalised, and provided with levees. Most of the alluvial area near Podivin was transformed to arable land. Due to elimination of floods, save for exceptions, areas denoted as wetlands and reed beds were qute dry for most of the year. As a result, the native fish communities typical of alluvial habitats gradually vanished from their habitats. In recent years, some 470 hectares on the left bank of the Dyje River, owned by a single private person, were transformed into a deer sanctuary. In the past two years, the arable land in that area has been gradually turned into meadows and a floodplain forest, together with restoring and enlarging the area of permanently waterlogged parts denoted as wetlands. As a result, the conditions permitting permanent occurrence of fish have been significantly improved and for a purposeful restoration of their fish communities in which native species predominate (the Carassius-Misgurnus type).
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