Sedlo National Nature Reserve

The Sedlo NNR was declared in 1968 on a territory of 51.97 ha and lies between the towns of Litoměřice and Úštěk in the Ústecký kraj – Ústí nad Labem Region. The subject of the protection is a massive tephrite ridge with steep slopes, deep scree layers which are mostly stabilised by natural deciduous forest growths, which are of a primeval charcter in parts. The rocks, which are shifted to the south, are covered with rare thermophilous flora. Sedlo is the highest peak of the Verneřické středohoří sub-unit (727 m) and dominates the Úštěcká kotlina - Úštěk Basin.
 
Sedlo is a volcanic Dome, built of sodalite tephrite, which is dark-grey in colour. Trachytic rock is found on the northern edge of the NNR territory and this has autometamorphosed to secondary minerals of many colours. The volcanic body stretches along a massive fault line running north–south and weathering has emphasized this feature. The mountain forms a long, sharp ridge with bizarre groups of rocks scattered around the summit and at the crossing of fault lines. The neovolcanic rocks on Sedlo thrust up through the Upper Cretaceous sediments of the Merboltice and Březno formations (calcareous claystones, kaolinic sandstones), which are prone to landslides. The border of both layers probably forms the edge of the detachment plane of many modern landslide streams in the near vicinity.
 
Thermophilous communities on the rocks with continental or continental – submediterranean elements pass into shrub-cover communities and again into forest stands, which cover the great majority of the NNR territory. Several specially protected plant species grow here, including basket of gold (Aurinia saxatilis), Alpine aster (Aster alpinus) –a weak population on the verge of extinction, the stool iris - Iris aphylla, perennial honesty (Lunaria rediviva), martagon lily (Lilium martagon) and older sources write of narrow-leaved helleborine (Cephalanthera longifolia) and red helleborine(Cephalanthera rubra).

The fauna in Sedlo NNR is of a forest character with several montane species represented. Research has identified 69 vertebrate species and protected species include the nutcracker (Nucifraga caryocatactes) and the pygmy owl (Glaucidium passerinum). Among the invertebrates there are abundant populations of the butterflies: lesser purple emporer (Apatura ilia) and poplar admiral (Limenitis populi) as well as the ground beetle Leistus montanus kultianus, which is bound to the exposed scree slopes.

The forest stands consist of thermophilous oak stands (upper section of the W slope), beechwoods with oak and hornbeam (lower section of W slope), beechwoods with woodrush (NW slope), lime – maple stands and maple stands with beech and elm (N + NE slopes) or a “mosaic” community on the southern slopes – beech stands with maple. A cultural spruce plantation is found on the edge of the NNR territory on the western slopes.

Near-natural forest management is practiced on the territory. The Sedlo ridge is accessible for visitors on marked tourist trails and has relatively high visitor numbers during the tourist season. Problems are caused by illegal camping (including campfires) in the summit and ridge areas.