National park: the Danube section

In this section, the gradient of the Danube is smaller, thus its speed is lower too, the river having a middle section character here. It meanders, building bars of silt and sand and constantly changing its course. The overdeveloped meanders were naturally cut through, creating backwaters and, in deeper areas, inland lakes. River regulation fundamentally changed this situation. In order to speed up the passage of icy floods and to facilitate navigation, the bends were cut through, and the river was constrained between dykes. The riverbed gradually deepened due to the higher velocity of the flowing water, and water level therefore sunk, resulting in a significant drop in the water table. On the Sárköz stretch of the river, the flood protection dykes were built relatively far from the river, on the boundaries of the Archbishopric of Kalocsa. This allowed Gemenc, one of the largest contiguous floodplains in Europe, to survive.

Until the end of the 18th century, local population did not try to prevent floods, but instead they worked on connecting more areas into this natural circulation. The massive amounts of water that arrived year after year was directed through a number of artificial canals called “fok” into lakes that could serve as fishing grounds, into depressions, hayfields, pastures and orchards. As the flood slowly came, people had time to evacuate their values and animals. This was called canal management which brought down the destructive force of floods to the minimum, at the same time providing a living for local people, mostly through abundant catches of fish. Apart from fishing, the most important form of farming in the floodplain was extensive keeping of horses and grey cattle. The operation of the system was made possible by the canal (“fok”) system. A single canal often supplied water to a series of lakes. Their maintenance required considerable skill and manpower. By the construction of the dykes, the Danube and the floodplain became disconnected, and the drop of water level also disrupted connection with the canals. Floods on the flood-prevented side vanished, and the areas there started to dry out and become filled up. The national park preserves the remnants of this natural floodplain habitat system and is of outstanding conservation value, as hardly any other such extensive floodplain wetland system remain in Europe.
The shoals and sandbars of the Danube are built from coarse sand, and because of that the habitats dry out significantly at low water levels. In such habitats willow bushes are found with purple willow and almond-leaved willow. On muddy sand flat shores and along oxbows there are willow groves which can be easily spotted from quite a distance by the silvery canopy of white willows. Normally flooded each spring, these groves can show a picturesque sight when masses of spring snowflakes, their typical spring flower bloom.
Oxbows in Gemenc appear stunning white in May from white water lilies, or yellow from yellow floating heart, both being protected species. The common mare’s tail, the only representative of its plant family living today, also flowers in May on the sandy substrate of the Béda oxbows. Common bladderwort, notable for its insect-eating nature, is also decorative when flowering. A relict species from the postglacial era, water chestnut has rhomboid leaves covering the water surface. In the past its fruits were harvested and eaten by people. Today it is a protected plant. Also quite frequent are two protected aquatic ferns reproducing with spores: water clover and floating fern. Aquatic vegetation is bordered from the land side by a belt of marsh plants, reed beds are then followed by tall sedge plant associations.
 
Oak-ash-elm gallery forests are located on higher floodplain terrain where water enters only at times of bigger flood waves. They are found both inside the inundation area and the flood protected side. The typical tree species of such forests are pedunculate oak, European white elm, and Hungarian ash. Under the trees there is a lush undergrowth, including the protected goat-leaf honeysuckle and wild grape. The pinkish-rusty, checkerboard-patterned flower, snake’s head fritillary is found in the herb layer. Surviving fragments of these species-rich forests are located in the Béda-Karapancsa area. Black hawthorn, a protected shrub, is an endemic species of the Lower-Danube Valley.
 
According to research carried out so far, 51 species of fish have been confirmed from the Danube area. Among the Danube fish, sterlet and burbot are still quite common. The typical predatory fish of the oxbows is pike. A wide variety of amphibians live in the area, and the most commonly seen reptiles are the grass snake and the European pond terrapin. The avian fauna of Gemenc and Béda-Karapancsa is of European importance, with populations of black storks and white-tailed eagles. The protection of Hungary’s largest black stork population is a priority of the national park. Building a huge nest high up in a tree and using it for decades, the white-tailed eagle is one of Europe's rarest birds of prey. The undisturbed nesting of both birds must be ensured, as they are the most sensitive to disturbance. The black kite is still common in the Béda-Karapancsa landscape. Because it is sensitive to changes in environmental effects, it is considered to be an indicator species. Among the herons, the reedbeds are nesting places for little egrets, great egrets, night herons, purple herons and a few pairs of Eurasian bittern. The common grey heron nests in willow groves. In the southern part of the area, the greylag goose has an insular occurrence. During the migration season, thousands of bird visitors find feeding and resting places in the floodplain. Ducks, geese and cormorants often winter here. Endangered bat species find refuge in the undisturbed forests. In holes of old trees, the pond bat and the barbastelle find daytime shelter and a roosting place to give birth to their young. The otter, adapted to an aquatic life, feeds on fish. The European beaver, because it became extinct in the 19th century, was reintroduced recently to the Gemenc area. Today it breeds successfully, making wildlife more diverse. Characterised by nocturnal activity, the wild cat prefers undisturbed woodlands adjacent to reedbeds. Red deer trophies taken in Gemenc are world famous. The population here is of outstanding genetics, with bulky yet finely proportioned body.