The Žákova hora mountain forest complex is located approximately 1.5 km north-east of the village of Cikháj. The NNR covers an area of 38.10 ha at elevations between 726 and 810 metres above sea level and has been preserved since 1933. This exceptionally well preserved segment of natural primeval forest communities on a richer locality in the higher part of the Žďárské vrchy hills is the biotope of a whole range of organisms which have already disappeared from the predominantly spruce-based stands which surround it, and is an important area for the study of forest development.
The rolling slopes with a predominantly south-western exposition and part of the flattened ridge of Mt. Žákova hora in the Devět skal hill country are built of migmatites and two mica gneisses of the Svratka Crystalline Complex intercalated with hornblende-biotite gneisses and amphibolites. On the weathering products on slopes we can find cambisols passing into cambic podzols in the summit areas with a local boulder cover. Gleysols and plano-gleyic luvisols are represented in areas of concentrated ground water discharge and in wet areas below the springs.
The forest communities in the reserve belong to the herb-rich beechwoods of the Eu-Fagenionalliance and to the Dentario enneaphylli-Fagetum and Festuco altissimae-Fagetum association. On humus-rich talus fragments elements of the Tilio-Acerion alliance can also be found usually in connection with the Cardaminion amarae alliance around the springs. Acidophilous spruce-beech stands which are close to the Calamagrostio villosae-Fagetum association can be found on the mineral-poor basement around the summit of Žákova hora. The predominant tree species is beech (Fagus sylvatica), with sycamore (Acer pseudoplatanus) and Norway maple (Acer platanoides), in the mix with spruce (Picea abies) in some places and also scattered examples of alder (Alnus glutinosa), wych elm (Ulmus glabra), ash (Fraxinus excelsior) and rowan (Sorbus aucuparia). Silver fir (Abies alba), which is one of the main tree species in a primeval forest is now absent from the reserve, although it is found in younger stands in the later extensions to the reserve. Notable herb species of the fir-beech forests flower in spring in the herb layer here, although they have disappeared from the surrounding spruce forests. These include nine-leaved toothwort (Dentaria enneaphyllos), coralroot (Dentaria bulbifera), dog’s mercury (Mercurialis perennis), sweet woodruff (Galium odoratum), bulbous corydalis (Corydalis cava), herb paris (Paris quadrifolia) and baneberry (Actaea spicata). The higher elevations are characterised by the presence of the stitchwort Stellaria longifolia and wood sedge (Carex sylvatica). In wetter areas and around the springs male fern (Dryopteris filix-mas), beech fern (Gymnocarpium dryopteris), Alpine enchanter’s nightshade (Circaea alpina) and wood speedwell (Veronica montana) can be found. At lower elevations spring snowflake (Leucojum vernum), mezereon (Daphne mezereum) and toothwort (Lathraea squamaria) may also be found. The lichen communities include Parmelia physodes, Parmelia sulcata, Parmeliopsis ambiqua, Cladonia fimbriata, Pyrenula nitidula and others. A rich bryoflora also grows in Žákova hora NNR with the mosses Amblystegium serpens, Isothecium alopecuroides, Orthotrichum stramineum, Paraleucobryum longifolium growing on the tree bark while the rotting tree stumps are the biotope of Tetraphis pellucida, Drepanocladus uncinatus, Brachythecium starkei, Herzogiella seligeri and on the humus substrate we can find Hypnum cupressiforme, Paraleucobryum longifolium, Mnium punctatum and Rhytidiadelphus triquetrus. The hoof fungus (Fomes fomentarius) and artist’s bracket (Ganoderma applanatum) help to give the reserve its primeval character and other decay fungi such as the cup fungus Plicaria repanda, purple jellydisc (Coryne sarcoides)and Lachnea hystrix break down the rotting wood and form suitable conditions for the continual renewal of the forests. Among the most significant fungi which grow in the reserve are plums and custard (Tricholomopsis decora), the shelf fungus Spongipellis delectans, the club fungus Clavariadelphus truncatus, orange chanterelle (Cantharellus friesii), the tooth fungus Hydnellum peckii, the falsebolete Boletopsis subsquamosa, the knight fungus Tricholoma robustum, the shelf fungus Cystostereum murrayi and others.
The occurrence of the ground beetles Carabus linnei, Carabus coriaceus, Carabus auronitens, Cychrus attenuatus, Pterostichus burmeisteri, Trechus pulchellus and Trechus splendens and the boreomontane ants Camponotus herculeanus, Manica rubida, Myrmica lobicornis, Formica picea, Formica lemani and Formica lugubris and many other invertebrates is bound to the preserved condition of this section of fir-beech forest of a primeval character. Among the vertebrates, the amphibians – Alpine newt (Triturus alpestris), common toad (Bufo bufo), common frog (Rana temporaria) and the reptiles – viviparous lizard (Zootoca vivipara) and the slowworm (Anguis fragilis) can all be found here. Birds which nest in the forest include black woodpecker (Dryocopus martius), great spotted woodpecker (Dendrocopos major), stock dove (Columba oenas), Tengmalm’s owl (Aegolius funereus), tawny owl (Strix aluco), red-breasted flycatcher (Ficedula parva), pied flycatcher (Ficedula hypoleuca) and nutcracker (Nucifraga caryocatactes), while the black stork (Ciconia nigra) nested here in the past. Important mammals include the Alpine shrew (Sorex alpinus), pygmy shrew (Sorex minutus), common shrew (Sorex araneus), field vole (Microtus agrestis), pine marten (Martes martes) and Liesler’s bat (Nyctalus leisleri). The forest complex is the home of a native population of red deer (Cervus elaphus).
This remote and almost untouched primeval forest was only visited in medieval times by wandering loggers who cut timber to produce charcoal for the nearby glassworks. However the forest was still able to regenerate naturally. The primeval forest remnants were disturbed in around 1900 when a strip of forest was clear-cut and replanted with spruces and in 1930 when a forest road was built across the southern edge. The original reserve had been protected since 1933 and was extended in 1990 and these stands are classified as a special purpose forest. Especially the upper parts of the forest are damaged by wind and hoar frosts and the spruces suffer from air pollution and diseases caused by decay fungi. Fungi often attack the trees after they were gnawed by red deer, which also graze on the tree seedlings. The historic core of the reserve is left to natural development processes and forms a height and spatially-differentiated four-layered forest stand with a natural mix of all stages of forest development from germinating seedlings, through growing young trees to the optimum and the breakdown of the massive old trees. Their trunks are broken down by many bracket fungi which give the forest its primeval character. These stands are rejuvenating well and advance growths cover around half of the territory, with sycamore predominating over beech. Management measures in the newer part of the reserve are differentiated. Little intervention is carried out in the stands with a near-natural composition; whereas the spruce dominated stands are being renewed and reconstructed with an underplanting of beech and fir. The aim is to form a mixed-age, spatially and height differentiated forest with a natural species composition.
A survey point in the basic trigonometric network in the Czech Republic was built on the summit of Žákova hora in 1946. The reserve serves to preserve the gene fund and also as an important object of scientific study of forest development processes. Žákova hora NNR is also at the core of the Supraregional Biocentre under the Territorial System of Ecological Stability. The Žákova hora themed nature trail had been built to lead visitors through the forests.