Description: The natural backbone of the territory is the Dyje river, which only has several small streams flowing into it on the NP territory (e.g. Gránice stream, Žlebský potok, Klaperův potok). Despite it seeming so small, the Fugnitz creek, which flows into the Dyje (Thaya) at Hardegg from the Austrian side is the largest tributary within the park. The Podyjí NP territory was shaped as a result of the erosive activities of the Dyje river, which has been carving into the originally flat landscape for millions of years to form a typical canyon with numerous meanders. Therefore, the Podyjí region should thank the Dyje river for its exceptional richness of living and non-living nature.
Flora: The river water crowfoot (Batrachium fluitans) grows abundantly in the Dyje river, while red algae (Hildenbrandia sp.) grow on rocks in the river in some places. Green algae (Cladophora sp.) and the common water moss (Fontinalis antipyretica) grow in the Dyje and its tributaries. The bankside growths along the river include significant amounts of the sedge Carex buekii and reed canary-grass (Phalaris arundinacea), while the yellow iris (Iris pseudacerus) is more localised. The growths of invasive plant species on the river banks, such as the Himalayan balsam (Impatiens glandulifera), Bohemian knotweed (Reynoutria x bohemica) and giant hogweed (Heracleum mantegazzianum), have been greatly reduced as a result of the yearly interventions by the Podyjí NP Administration to remove them.
Fauna: The most important water flow is the Dyje river, the fauna of which is strongly influenced by the existence of the Znojmo and Vranov Reservoirs, which greatly restrict animal migrations. The operation of the Vranov Hydroelectric Plant also fundamentally changes the hydrological conditions in the river. The greatly modified fish stocks in the Dyje are also due to the hydroelectric plant. At present there is a predominance of species of the “trout belt”, whereas the native populations of fish such as the nase (Chondrostoma nasus) and barbel (Barbus barbus) have almost disappeared. Bullheads (Cottus gobio) live here in large numbers. Birds which are relatively common along the Dyje and its tributaries include the dipper (Cinclus cinclus), while the kingfisher (Alcedo atthis) is less abundant. Several fish-eating species gather on the river in the wintertime, including large number of cormorants (Phalacrocorax carbo).
Author: Robert Stejskal