The NNR in the Moravskoslezské Beskydy mountain range covers the summit areas of Mt. Kněhyně (1257 m) and the Čertův mlýn Massif (1206 m) which are divided by a shallow saddle. The NNR was declared in 1989 on a territory of 195 ha at elevations between 940 and 1257 metres, and lies to the south of the municipality of Čeladná in the Moravskoslezský kraj – Moravian-Silesian Region and within the Beskydy PLA. The subject of the protection is the unique remnants of natural high mountain forest growths with numerous rocky outcrops and pseudokarst phenomena.
The region lies in the centre of the Godula facies of the Flysh units. The steep slopes are modelled by strong fluvial erosion, especially in the spring basins of the Bystrý, Magurka and Kněhyně streams. The slopes are covered with a bouldery apron and the Bystrý potok stream amphitheatre has the character of a boulder field. Both summits are surrounded by a wreath of rock formations. The western slope of Čertův mlýn and the eastern slope of Kněhyně are affected by old landslides and have a dissected relief with numerous pseudokarst landforms. The soil cover is of shallow skeletal Podzols.
At lower elevations, on leeward and south-facing slopes the natural forest type is beech forest with nine-leaved toothwort (Dentaria enneaphyllos) of the Dentario enneaphylli-Fagetum association. The tree layer is dominated by beech (Fagus sylvatica) with smaller proportions of sycamore (Acer pseudoplatanus), silver fir (Abies alba) and Norway spruce (Picea abies). The herb layer includes baneberry (Actaea spicata), sanicle (Sanicula europaea), nine-leaved toothwort (Dentaria enneaphyllos), coralroot (Dentaria bulbifera), wood barley (Hordelymus europaeus), and bilberry (Vaccinium myrtillus). In the mountain beech forests of the Aceri-Fagetum association the herb layer is dominated by Alpine lady fern (Athyrium distentifolium) along with other species including large white buttercup (Ranunculus platanifolius) and Alpine sow-thistle (Cicerbita alpina). Mountain spruce forest of the Athyrio alpestris-Piceion association can be found at the highest elevations. Here the tree layer is dominated by Norway spruce (Picea abies) with relatively large numbers of rowan (Sorbus aucuparia). The herb layer consists mostly of ferns such as holly fern (Blechnum spicant) with hairy small-reed (Calamagrostis villosa) and bilberry (Vaccinium myrtillus) in the summit areas. The open forest areas are also the home of the Moravian stiff monk’s-hood (Aconitum firmum subsp. moravicum).
The oldest tree layer on the summits is mostly dead as a result of the effects of physical age, air pollution and bark beetle infestations. Very successful natural rejuvenation of the tree growths is taking place under the protection of the dead standing trees and fallen trunks.
The Kněhyně – Čertův mlýn NNR, along with several others Beskydy mountain peaks are the only localities in the Czech Republic where our only species of blind ground beetle - Pseudanophthalmus pilosellus lives. This Carpathian species is found nowhere else in the Czech Republic.
Many bird species are bound to the mountain forest biotopes, including the hazel hen (Bonasa bonasia), three-toed woodpecker (Picoides tridactylus), white-backed woodpecker (Dendrocopus leucotus), raven (Corvus corax) and red-breasted flycatcher (Ficedula parva). The NNR territory is one of the last places in Beskydy where the capercaillie (Tetrao urogallus) may still live. The lynx (Lynx lynx) finds ideal conditions on the steep, vegetation-covered slopes of Kněhyně and Čertův mlýn. Brown bears (Ursus arctos) have been observed on the Kněhyně massif several times in recent years. There are strong red deer (Cervus elaphus) populations on the remote slopes and in the stream valleys.
Widespread areas of natural forest growths have survived on both of these remote and inaccessible peaks – these growths are now approximately 160 – 180 years old. Most of the oldest trees have died off as a result of physical age and air pollution but successful natural rejuvenation is taking place. The old forest growths are disintegrating and the regeneration phase is beginning. The south-eastern slopes of Čertův mlýn and the western slope of Kněhyně were considerably affected by human activity before the reserve was declared. After the growths which had been damaged by air pollution and the rapid temperature changes around New Year in 1979 these cleared areas were replanted predominantly with non-native spruces. A small mountain meadow can be found on the saddle between the peaks and was formerly used for sheep grazing. Part of the NNR will be left to develop by natural processes.
To visit the NNR we recommend that you set out on the red trail from the Pustevny mountain saddle (which we can reach by chairlift from Trojanovice). From the NNR border on the saddle below Mt. Tanečnice we will have a demanding ascent to the summit, in the direction of Martiňák we can find an unusual rock formation in the forest – Čertův stůl – the “Devil’s Table” which may remind us of a Megalithic structure. After this short diversion we will continue along the red trail and descend to the north to the Kněhyňská louka meadow. Here we can find a memorial to Second World War partizans, the ruins of a mountain cottage and a turning to a spring. We continue to walk down through the mountain forests to crossing of trails by the hunters’ cottage and then follow a wide forest road to the painted, wooden chapel in the Čeladenka stream valley at the upper boundary of the municipality of Čeladná.