Dobroč

Dobročský prales National Nature Reserve, Slovakia

Dobročský prales was established as early as 1913 1. The area was originally 50 ha and was later enlarged to 102 ha 1. Dobročský prales has been thoroughly studied. The main tree species in the original part are European beech (Fagus sylvatica), European silver fir (Abies alba) and Norway spruce (Picea abies). There are only a few other tree species, like sycamore maple (Acer pseudoplatanus), Norway maple (A. platanoides) and European ash (Fraxinus excelsior). The original part is very close to its natural state1, but silver fir seedlings are missing – a result of herbivore over-population in this region. Thus, the proportion of silver fir in Dobročský prales has decreased during the last decades1 and will further decrease if the herbivore pressure remains high. The situation is remarkably better in eastern Slovakia (see Stužica National Nature Reserve). European spruce bark beetle (Ips typographus) has killed some spruce in recent years. The newer part of Dobročský prales is dominated by spruce and is less natural. There is an overgrown old road through the reserve. Otherwise, no traces of human use, like cut stumps, are visible in the original part.

The forest is productive, and all the tree species reach great heights. My search for tall trees in 2015 and 2020, using Nikon Laser 550A S and TruPulse 200X instruments, revealed following maximum heights: Norway spruce 58.1 m, silver fir 56.1 m, beech 46.4 m and sycamore maple 39.85 m. There are several Norway spruce and silver fir at least 54 m tall. Of the deciduous trees, I measured only a few individuals, so still taller trees may well exist. A silver fir tree fallen several decades ago had a diameter of 193 cm and a volume of 55 m3 1. Silver fir reaches in Dobročský prales the age of 450 years, Norway spruce approx. 350 and beech 220–250 years 1. There is large amount of dead wood. Extremely rare wood-decay fungi, considered as virgin forest indicators, have been found in the reserve, e.g. Antrodiella citronella and Phlebia centrifuga2. The shrub layer is sparse, being mostly beech saplings. The field layer is sparse, too, due to the shady north-facing slope, and is dominated by sweetscented bedstraw (Galium odoratum), wood sorrel (Oxalis acetosella), yellow archangel (Lamiastrum galeobdolon), sanicle (Sanicula europaea) and ferns. Overall the reserve, with its large old trees (photo below) and the high amount of deadwood, gives a very primeval and aesthetic impression.

Large beech (foreground) and fir (left)

Dobročský prales is located on a relatively gentle north-facing slope at elevations 720–1005 m. Annual precipitation is 890–960 mm and average annual temperature 4.5–5°C 3. The bedrock consists of granodiorites, granites and diorites3. The soils are productive3.

KR & TM

References:

  1. Korpel’, Š. (1995): Die Urwälder der Westkarpaten. Gustav Fischer Verlag.
  2. Holec, J. et al. (2018): Old-growth forest fungus Antrodiella citrinella – distribution and ecology in the Czech Republic. Czech Mycology 70(2): 127–143, (online version, ISSN 1805-1421).
  3. Saniga, M. & Schütz, J.-P. (2001): Dynamik des Totholzes in zwei gemischten Urwäldern der Westkarpaten im pflanzengeographischen Bereich der Tannen-Buchen- und der Buchenwälder in verschiedenen Entwicklungsstadien. Schweiz. Z. Forstwes. 152 10: 407–416.