Boky National Nature Reserve, Slovakia

Boky Reserve (1.8 km2) lies on a south to southwest facing steep slope at 280–590 m elevation1. The steep south facing slope makes the site drier than might be predicted from the annual precipitation (720 mm). Average annual temperature is about 7.5°C. The bedrock consists of andesite and tuff2.

Dominant in the upper canopy are sessile oak (Quercus petraea) and Turkey oak (Q. cerris) (photo below). Many small tree species grow under them; the most abundant include European hornbeam (Carpinus betulus), field maple (Acer campestre), Cornelian cherry (Cornus mas) and hawthorns (Crataegus spp.). Forest is low on steep slopes but in the side valleys the oaks become fairly large and less drought-resistant species also occur, e.g. European beech (Fagus sylvatica) and sycamore maple (Acer pseudoplatanus). The tallest trees are slightly over 30 m. As Boky is mostly too dry for beech, tree species diversity is relatively high in the Central European context. The herb layer is fairly rich.

Turkey oak dominated slope forest. Also sessile oak (less furrowed bark and the branch, top left foreground)

Boky is an important reserve as very little almost untouched dry oak forest still remains in Europe. Some parts of Boky Reserve have probably been used for grazing in the past, but for a long period there has been no human influence2. The oldest oaks are more than 300 years old 2.

A marked hiking trail leads through Boky Reserve. It starts from the car park at 48°34’10.6″N 19°02’53.2″E. In the valley below the reserve there is a highway, which means a lot of noise in the lower reserve. Boky’s best-known attraction is a large balancing rock “Čertova skala” (”Devil’s Rock”).



  1. Korpel’, Š. (1995): Die Urwälder der Westkarpaten. Gustav Fischer Verlag.