Žehuňský rybník National Nature Reserve

The NNR was declared in 1948 on an area of approximately 300. The subject of the protection is the Žehuňský rybník fishpond, the littoral reedbeds which surround it and the neighbouring hygrophilous and mesophilous meadows. Žehuňský rybník NNR is a part of the Žehuňský rybník – Obora Kněžičky SPA – Bird Area to protect the little bittern (Ixobrychus minutus) and the spotted crake (Porzana porzana) and a part of the proposed Žehuň Site of Community Importance, to protect the narrow-mouthed whorl snail (Vertigo angustior).

The NNR lies in the county of Nymburk, in the Středočeský kraj - Central Bohemian region. The geological substrate is formed of sandy marlstones and calcareous sandstones of Middle Turonian age, overlain by sand and gravel deposits, on which floodplain soils and gleyic fluvisols have developed. The Žehuňský rybník fishpond lies on the Cidlina river, which flows through it, and is of an oval shape stretching E-W. The Cidlina river splits into several branches before it enters the pond and a canal has been built to divert water around the south side of the pond. The reserve belongs to a warm climatic region and lies at elevations of around 203 metres above sea level.

The aquatic vegetation in the fishpond is represented by growths of yellow water-lily (Nuphar lutea) in the upper part of the fishpond and pondweeds, especially fennel pondweed (Potamogeton pectinatus), in the bypass canal, and lesser growths of curled pondweed (Potamogeton crispus). The arrowhead (Sagittaria sagittifolia) is relatively common here and flowering rush (Butomus umbellatus) has also been recorded. Littoral reedbeds are also found around the pond in which the greater spearwort (Ranunculus lingua) also grows. The reedbeds merge into meadow communities. The most valuable are the fen meadows which are very rare in the area and often form a mosaic with moor-grass (Molinia) meadows. Endangered species which grow here include early marsh orchid (Dactylorhiza incarnata), blue moor-grass (Sesleria uliginosa), Davall sedge(Carex davalliana), adderstongue(Ophioglossum vulgatum) and the garlic Allium angulosum. A unique feature is the occurrence of several species of the marsh dandelion Taraxacum sect. palustria.

Sedge growths predominate on the south bank of the pond, most often with the dominant species – lesser pond sedge (Carex acutiformis), which merge into the meadowsweet (Filipendula) grasslands.

On the north side of the pond the reedbeds are bordered by thistle (Circium) meadows and these are followed by mesophilous meadows which are herb-rich in places and grass-dominated in others. Interesting subhalophytic vegetation with strawberry clover (Trifolium fragiferum) can be found on a small pasture near the village of Žehuň.
 
The Žehuňský rybník fishpond hosts a rich population of swan mussels (Anodonta cygnea), which are a vulnerable species and are becoming rarer. Thanks to the fact that the Cidlina river flows through the pond the specially protected painter’s mussel (Unio pictorum) also occurs here.

Amphibians which can be found here include common tree-frog (Hyla arborea), European fire-bellied toad (Bombina bombina) and marsh frog (Rana ridibunda).

The littoral reedbeds are a significant biotope for water birds. The little bittern (Ixobrychus minutus), spotted crake (Porzana porzana), little crake (Porzana parva) and water rail (Rallus aquaticus) all nest here and the bearded tit (Panurus biarmicus) is also thought to nest here. White-tailed eagles (Haliaeetus albicilla), which nest in the nearby hunting preserve, regularly fly here to hunt their food.

The Žehuňský rybník was built in 1492. At present semi-intensive fishfarming is carried out here. The most valuable semi-waterlogged meadows have not been cultivated in recent years. The drier meadows are cut twice a year and the small meadow near Žehuň is used as a pasture for a small flock of sheep. The NNR is not easily accessible and no trails pass through the area except for the path to the Choťovice railway station on the north bank. The meadows on the south bank are accessible over a bridge from the Korce farm.