Prameniště Blanice – The Springs of the Blanice River is the youngest National Nature Monument in the Czech Republic as it was declared in 2008 on an area of 277 hectares. The territory belongs to the Želnavská hornatina Hilly Region and lies in the Jihočeský kraj – South Bohemian Region. This new national nature monument lies between the Blanice NNM and the Boletice Military Training Area. The protected area covers the spring area, headwaters and alluvial plain of the Blanice river, the alluvial plains of its tributaries – the Pucharenský, Černý and Spálenecký potok Streams, and their tributaries. The most extensive part of the monument covers wetlands and marshes at various stages of development. The monument was declared to protect the biotope in which a population (at an early stage of development) of the rare and critically endangered freshwater pearl mussel (Margaritifera margaritifera) occurs.
The pearl mussels require very pure, oligotrophic (nutrient-poor) water with xenosaprobic to oligosaprobic characteristics for their development. The conditions which are necessary for the development of young mussels are constant water temperature, sufficient food supplies, permeability of the stream bottom sediments together with the maintenance of further suitable chemical and physical conditions such as the ion - strength, pH of the water, water turbidity – which does not lead to destabilisation of the natural organic suspensions in the flow.
The main management task at the monument is to maintain suitable conditions for the life of the pearl mussels. This involves maintaining the current landscape character with a mosaic of alluvial forest stands, wetlands and meadows. It is essential that the large-scale planting of spruce monocultures in the area is stopped, and that disturbance to the soil surface and drainage work in the surrounding forests are restricted. The requirements for the existence and development of the population of pearl mussels are to maintain the water purity and to prevent any kind of water pollution in the Blanice catchment.
Other specially protected organisms also occur at Prameniště Blanice NNM. The specially protected plants include the endangered arnica (Arnica montana), broad-leaved marsh orchid (Dactylorhiza majalis), mountain snowbells (Sildanella montana), monkshood (Aconitum plicatum) and the false leopardsbane Doronicum austriacum. The highly endangered moorland clouded yellow butterfly (Colias palaeno) lives on the bog whortleberries and the endangered poplar admiral (Limenitis populi) can occasionally be seen around the bankside stands with aspen trees. The brook lamprey (Lampetra planeri) and the bullhead (Cottus gobio) live in these clear waters, as do the Alpine newt (Triturus alpestris) and occasionally the smooth newt (Triturus vulgaris). The adder (Vipera berus) represents the reptiles at the monument. The protected otter (Lutra lutra) migrates along the Blanice river and its tributaries. The territory of the national nature monument supports several rare bird species, including the kingfisher (Alcedo atthis), whinchat (Saxicola rubetra), corncrake (Crex crex), snipe (Gallinago gallinago), as well as the highly endangered black grouse (Tetrao tetrix) and hazel hen (Bonasa bonassia).