Hrdibořické rybníky National Nature Monument

The Hrdibořické rybníky – Hrdibořice Fishponds NNM and the surrounding meadows lie on the right bank of the Blata stream on the northern edge of the village of Hrdibořice in the Olomoucký kraj – Olomouc Region in central Moravia. The national nature monument covers an area of 37.7 hectares at an elevation of 206 metres above sea level.
This territory is of special significance due to the extent of the fenny soil substrate, which makes it one of the most important fenland habitats in Moravia. The protected area is a notable sanctuary for rare plant and animal species in the middle of an intensively farmed landscape.
The main subjects of the protection are two critically endangered plant species, the marsh angelica (Angelica palustre) – which has its only locality in the Czech Republic here, and the narrow-fruited watercress (Nasturtium microphyllum) which has one of only two localities in the Czech Republic here.
The geological basement under the territory consists of Tertiary calcareous sand and gravel sediments, which are overlain by organosoil of the fen type which developed here in the Quaternary period. The layer of fen soil here is between 4 and 6m in depth and peat from this seam was extracted commercially between 1938 and 1963. Two pools formed on the sites of the former extraction, and they are known as the Raška and Husák fishponds.
The meadow growths on the territory were ploughed up in the 1980s, but renewed after the declaration of the protected area in the 1990s. The species composition of these renewed meadows is only improving very slowly but work is being carried out to renew the population of the marsh angelica. Their representation on parts of the meadow has now been stabilized and hundreds of marsh angelica flowers can be seen here every year. On the meadow we can also find marsh sow-thistle (Sonchus palustris) and square-stalked St. John’s wort (Hypericum tetrapterum). In the shallow, damp ditches and in their bankside growths we can find greater pond sedge (Carex riparia), hop sedge (Carex pseudocyperus), hemp agrimony (Eupatorium cannabinum), berry catchfly (Cucubalus baccifer), green figwort (Scrophlularia umbrosa) and skullcap (Scutellaria galericulata).
The narrow-fruited watercress (Nasturtium microphyllium) grows in the Podolší drainage ditch along the border of the protected area, along with lesser water parsnip (Berula erecta), flowering rush (Butomus umbellatus), branched bur-reed (Sparganium erectum) and other wetland plants.
Aquatic plants which can be found in the fishponds include the holly-leaved naiad (Najas marina), rigid hornwort (Ceratophyllum demersum), curled pondweed (Potamogeton crispus), fennel pondweed (Potamogeton pectinatus) as well as stoneworts (Chara sp.). When the water levels in the ponds are lower we can find plants such as brown galingale (Cyperus fuscus) and celery-leaved buttercup (Ranunculus scleratus) growing on the exposed bottom areas. The margins of the ponds support large growths of common reed (Phragmites australis), bulrush (Typha latifolia) and lesser bulrush (Typha angustifolia).
The fishponds and other smaller water-filled hollows and ditches are used by amphibians such as the agile frogs (Rana dalmatina), edible frogs (Rana esculenta synkl.), fire-bellied toads (Bombina bombina) and the European tree frog (Hyla arborea) and common toad (Bufo bufo) also live on the territory. Water birds which can be observed in the monument include the little grebe (Tachybaptus ruficollis), great crested grebe (Podiceps cristatus), grey heron (Ardea cinerea), moorhen (Gallinula chloropus), kingfisher (Alcedo atthis) and occasionally the little bittern (Ixobrychus minutus). Marsh harriers (Circus aeruginosus), sedge warblers (Acrocephalus schoenobaenus) and marsh warblers (Acrocephalus palustris) nest in the bankside growths and reedbeds. Fish species which live in the ponds include the bitterling (Rhodeus sericeus), crucian carp (Carassius carassius) and the moderlieschen or “motherless minnow” (Leucaspius delineatus).
In addition to tree species which reflect the locality conditions, such as alder (Alnus glutinosa), ash (Fraxinus excelsior) and bird cherry (Prunus padus), the woodland stands in the protected area are predominantly formed of non-native hybrid black poplars (Populus x canadensis) and ashleaf maple (Acer negundo). However, these trees and the accompanying shrub growths are a sanctuary for many bird species such as the nightingale (Luscinia megarhynchos), blackcap (Sylvia atricapilla), penduline tit (Remiz pendulinus), spotted flycatcher (Muscicarpa striata) and the golden oriole (Oriolus oriolus).