Lužní potok National Nature Monument

Lužní potok (Stream) NNM covers an area of 123ha at elevations of 551-613 metres above sea level and was declared in 1989. The Lužní potok Stream forms the natural border between the Czech Republic and Germany (Bavaria) to the west of the towns of Hranice and Aš in the Karlovy Vary Region and together with several tributary streams it is the home of the critically endangered freshwater pearl mussel (Margaritifera margaritifera). A joint Czech-Bavarian project has been prepared for the border section of the stream (“Management plan for the water in the border section of the Lužní potok Stream”). On the basis of the management plan, interventions are carried out to preserve the current populations of aquatic animals and to improve the conditions for their reproduction.
The majority of the protected area covers the alluvial plain of the Lužní potok Stream with sandy-clayey and loamy-clayey flood sediments. The basement under the neighbouring forested slopes of Smolnice Hill (607m) is built of chlorite-sericite phyllite, which also includes quartzite.
A large part of the territory is forested with spruce and pine stands, with an admix of beech (Fagus sylvatica) and silver birch (Betula pendula). Along the banks of the Lužní potok Stream the tree layer is made up of alder (Alnus glutinosa) and several species of willows (Salix sp.).
On the stream alluvial plain and in the small peatbogs we can find significant plant species for the protected area such as the cranberry Oxycoccus palustris, broad-leaved marsh orchid (Dactylorhiza majalis), bogbean (Menyanthes trifoliata) and small bur-reed (Sparganium minimum). The rare red algae Batrachospermum moniliforme has been recorded in the stream.
The most important species and the main subject of the protection in the national nature monument is the freshwater pearl mussel (Margaritifera margaritifera). The stream is also the home of abundant populations of broad-fingered crayfish (Astacus astacus) and brook lamprey (Lampetra planeri).