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Ichtyofauna of the border Malše River
Matěnová, V. ; Matěna, Josef
Ichthyological investigation of the border section of the Malše River was performed in 2002 and 2003. The occurrence of brook lamprey larvae and five rheophilous fish species was confirmed – brown trout, common sculpin, grayling, burbot, stoneloach. Species escaping from fishponds – perch and common carp were found in negligible numbers. The brown trout dominated in numbers at all investigated profiles. The length and age analysis of the brown trout population showed the dominance of YOY fish, the population exhibited a harmonical age class composition. Results confirmed successful natural reproduction of trout, grayling, burbot and bullhead. The following investigation in 2003 oriented specially on the occurrence of brook lamprey proved that the population remained unaffected by the floods in 2002. The border Malše River represents an athropogenically slightly affected watercourse with suitable conditions for natural reproduction of all indigenous species found during the study.
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Soil macrofauna (Diplopoda, Chilopoda, Oniscidea) under restored flood conditions in meadow and forest habitats in South Moravia, Czech Republic
Tajovský, Karel
Floodplain habitats in the alluvium of the Morava and Dyje rivers, Czech Republic, were strongly affected by changes in water regime conditioned by regulation measures in the past centuries. These negative changes resulted in the cessation of regular floods, decline of groundwater level and subsequently in dramatic changes of characteristic vegetation as well as animal assemblages. Therefore activities aimed at more thorough analysis and restoration and revitalization projects were undertaken in nineties. Specific extreme conditions in the regularly flooded biotopes are determining for the existence of the specific soil invertebrate assemblages including millipedes (Diplopoda), centipedes (Chilopoda) and terrestrial isopods (Oniscidea). Long termed pitfall trapping processed in forest and meadow habitats in the years 1993-2001 enable us to evaluate the impact of restoration of regular floods and improving water regime on these terrestrial invertebrates. While the animal assemblages in floodplain forest (Ranšpurk National Nature Reserve) showed to be more conservative towards restoration processes, those in flooded meadow (Křivé jezero National Nature Reserve) dramatically stressed by previous negative conditions well responded to improving water regime. Renewed inundations at this locality contributed to the return of parameters of natural wetland habitat. Low densities and the species typical for extreme flood conditions (centipede Lamyctes emarginatus, millipedes Julus scanicus and Leptoiulus cibdellus, terrestrial isopod Trachelipus rathkii) were monitored at this locality.
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