The Kopičácký rybník Pond NNM was declared in 2007 on an area of 8.3 ha to protect communities of plants and animals which are bound to the aquatic environment of the Kopičácký rybník Pond including the surrounding littoral growths and fen meadows. This territory had been included in an extensive protected area since 1948 and was a part of the Žehuňská obora and Žehuňský rybník National Nature Reserve from 1992. The national nature monument is a part of the Žehuň – obora Site of Community Importance and the Žehuňský rybník – Obora Kněžičky SPA – Bird Area.
The Kopičácký rybník Pond lies close to the eastern border of the Středočeský kraj – Central Bohemian Region and around 3km south of the town of Městec Králové. The monument covers a forest-free enclave inside the Obora Kněžičky (Kněžičky Game Reserve) forest complex and is out-of-bounds to the general public all year round. The protected area lies at elevations of around 235 metres above sea level in a warm climatic region and on the upper plateau of the Hradčanská Questa in the spring area of the Dlouhopolský potok Stream. Due to the weak flow levels in the stream, only partial regulation of the water level in the pond is possible. The geological basement is built of marly sediments from the Mesozoic period, which are overlain by pelic Chernozem and Quaternary fenny sediments.
The open water surface of the Kopičácký rybník Pond covers an area of around 2.5ha and serves as a breeding site for a number of species of frog including the marsh frog (Rana ridibunda). If the level of fish stocking allows for the development of aquatic plants, the majority of the fishpond bottom is covered with stoneworts, especially Chara hispida. This species can also be found in the pools on the fen meadow.
The littoral growths around the Kopičácký rybník Pond are predominantly formed of common reed (Phragmites australis), with bulrush (Typha latifolia) and common club-rush (Schoenoplectus lacustris) in places. Where the red growths are of lower density we can also find sedges in the undergrowth, including hop sedge (Carex pseudocyperus). The most interesting areas, from the botanical and zoological standpoints, are the areas of very sparse reedbeds with the scattered occurrence of tall sedges. The water level is only tens of centimetres deep here in the springtime and in the autumn the water table falls below ground level. We can find the small yellow sedge (Carex viridula) here, along with the rarest plant at Kopičácký rybník NNM – the various-leaved pondweed (Potamogeton gramineus), which currently grows at less than 10 localities in the Czech Republic. The tiny mollusc – the ramshorn snail (Anisus vorticulus), which is a species of community interest, was re-discovered for the Czech Republic in this biotope in 2008. Dragonflies are also well represented and 13 species have been recorded here.
The fen meadow with the dominant moor-grass Sesleria uliginosa and an area of around 4ha is one of the most extensive low moors in the Czech Republic. Smaller sedge species which grow here include davall sedge (Carex davalliana), carnation sedge (Carex panicea), the sedge Carex tomentosa, tawny sedge (Carex hostiana) and glaucous sedge (Carex flacca). A rich population of the tiny mollusc – narrow-mouthed whorl snail (Vertigo angustior), which is a species of Community interest is also bound to the fen meadow and the entire mollusc community is classified as a relict population, which closely resembles the mollusc populations found on “prehistoric Labe meadows”.
Before the Kopičácký rybník Pond was declared as a separate protected area, the meadow was only maintained by grazing of game animals kept in thegame reserve.
Blue moor-grass (Molinia caerulea) and locally the wood small-reed (Calamagrostis epigeios) expanded to cover areas with a lower water table. Weaker and less competitive species such as adderstongue (Ophioglossum vulgatum) and broad-leaved marsh orchid (Dactylorhiza majalis) gradually retreated from the fen meadow. For this reason the meadow has been regularly cut since the national nature monument was declared.
The communities which are bound to the fishpond biotope are strongly influenced by the numbers and species composition of the fish stocks. The stocked fish are predominantly carp and restrict the development of the other elements of the ecosystem by eating them, but also by rooting around in the marly fishpond bed and strongly clouding up the water. The cloudy water negatively influences the development of submerged and floating aquatic plants, the amphibian communities whose larvae develop in these waters and also the birds, which have difficulty finding food in such cloudy water. On the contrary, if the fish stocks were removed, then the fishpond would rapidly become overgrown by the littoral reedbeds. Therefore it is necessary to continually search for the optimum composition and density of fish stocking to allow the highest possible diversity of all life forms which are bound to the aquatic environment, but on the other hand to permanently maintain the fishpond biotope and look for new methods of fulfilling these aims.