Dobra Primeval Forest, Austria

Dobra, protected since 1910, is despite its small area (12.3 ha) an important and interesting reserve, for its low elevation, optimal growth conditions and untouchedness¹. The forest was saved because transporting timber from the deep valley was very difficult until about 1970 ¹. No direct human traces can be seen in the forest.

Dobra consists of a northeast–southwest orientated ridge and the adjoining slopes. The northwest-facing slope is very steep, the southeast-facing one less so. European beech (Fagus sylvatica) dominates. Wych elm (Ulmus glabra) was until 1974 the second-most abundant tree. At that time, Dutch elm disease (Ophiostoma spp.) reached the locality and the last larger wych elms were infected in 1977 ¹. Even today, young wych elms can still be found but all the larger trees are gone. Particularly on the ridge there are also large-leaved lindens (Tilia platyphyllos, photo below). Black elder (Sambucus nigra) is abundant as shrubs or small trees. The other, much less common trees are sycamore maple (Acer pseudoplatanus), Norway maple (Acer platanoides), European hornbeam (Carpinus betulus), European ash (Fraxinus excelsior), Norway spruce (Picea abies), European silver fir (Abies alba) and European rowan (Sorbus aucuparia) ^{1 2}. Conifers Norway spruce and silver fir are not competitive here². In addition, air pollution has killed the larger silver firs³. Roe deer (Capreolus capreolus) and red deer (Cervus elaphus) overpopulations have a strong effect on tree regeneration, preventing sycamore maple from replacing wych elm as a pioneer tree¹. Beech, instead, regenerates effectively.

On the wind-protected, microclimatically favourable¹ and less steep southeast-facing slope, there are very large beeches (girths up to 456 cm, one of the thickest known forest-grown beeches⁴). On the footslope at the eastern end of Dobra, there are also a few very tall beech: the tallest tree I measured in 2017 (with TruPulse 200X laser) was 47.4 m. The tallest tree of Dobra had a girth of only 212 cm. Before the Dutch elm disease, wych elm reached 154 cm diameter ². Besides the impressive tree growth, the high fertility of the soil can be seen from the luxuriant and impressive herb layer, which includes perennial honesty (Lunaria rediviva) and wild garlic (Allium ursinum). On the steep northwest-facing slope the wood volumes and the growth rates are much lower ³. Elevation is 390–550 m, annual precipitation 650 mm and average annual temperature 7°C ¹. The base rock is Gneiss².

KR & TM

References:

1. Mayer, H. & Reimoser, F. (1978): Die Auswirkungen des Ulmensterbens im Buchen-Naturwaldreservat Dobra (Niederösterreichisches Waldviertel). Forstwissenschaftliches Centralblatt 97, 314–21.
2. Mayer, H. (1971): Das Buchen-Naturwaldreservat Dobra/Kampleiten im niederösterreichischen Waldviertel. In Mayer. H. (ed.) 1987: Urwaldreste, Naturwaldreservate und schützenswerte Naturwälder in Österreich. Institut für Waldbau, BOKU.
3. Augustin, B.: Aufbau und waldbauliche Beurteilung des Buchen-Urwaldreservates Dobra II im Kamptal. Diploma thesis, BOKU.
4. https://www.monumentaltrees.com/en/