baumzaehlen - Primeval Forests & Their Trees

©2017copyright christoph hase

Heilige Hallen Nature Reserve, Germany

Together with one or two other small reserves, the core zone of this nature reserve is the most natural lowland Opens internal link in current windowFagus sylvatica (European beech) forest in Germany (see also Opens internal link in current windowFauler Ort Nature Reserve). The oldest trees have germinated in approx. 1700. Strictly speaking, it is not a primeval forest as it is known that the site was not forested during the Thirty Years' War (1618-1648). In 1850, when the forest was approximately 150 years old and in the late optimal phase, Grand Duke Georg von Mecklenburg-Strelitz protected 0.25 km2 of the impressive tall forest "for all time". Since then, there has been no wood cutting, but dead wood was removed until 1950. As the mortality of the old trees has markedly increased only after 1950, this has probably not a marked influence on the state of the reserve, a path leading through the forest being the only visible sign of human influence. A buffer zone has been added later, and the total area of the reserve is now 0.6 km2. 1

Elevation is 120–140 m, annual precipitation 589 mm and average annual temperature 7.9°C 2. The original F. sylvatica are now dying, the tall canopy is open, and in the canopy gaps there is dense new growth of young F. sylvatica. In the literature the maximum height of the F. sylvatica in the reserve is given as over 50 metres, but this seems exaggerated at the moment. Together with Jeroen Philippona* our Opens external link in new windowsearch for tall trees revealed current maximum heights of 43 metres, using Nikon 550 instruments. However, the forest has certainly been taller in the past. Thick dead branches over 40 metres above the forest floor are a sign that the trees must have been taller in the past. The record reliably measured F. sylvatica used to be 49.3 m but the tree has now lost its top; it was also situated in Germany3.

The forest is pure F. sylvatica with the exception of a small amount of Opens internal link in current windowCarpinus betulus (European hornbeam). Without human impact, most of Central Europe would be dominated by F. sylvatica; reasons for its extraordinary role include its wide climatic, edaphic and shade tolerances (the minimum requirement is only 1-2% of sunlight4) and longevity5. Natural stands dominated by other tree species are restricted to extreme sites (e.g. wet, dry or cold) outside their growth optimum6, where F. sylvatica is unable to form a closed canopy7.


After a ban of a few years, entry to Heilige Hallen is again permitted. In 2015, the official site was not yet updated in this respect. Under the canopy, the undergrowth is very sparse to non-existent making walking very easy. Camping is not permitted.


* Jeroen's www-site:




1    Sperber, G. & Thierfelder, S. (2005): Urwälder Deutschlands. BLV Verlagsgesellschaft mBH.



4       Lyr, H., Fiedler, H. J. & Tranquillini, W. (1992): Physiologie und Ökologie der Gehölze. Fischer.

5       Jahn, G. (1991): Temperate deciduous forests of Europe. In Röhrig, E. & Ulrich, B.: Temperate Deciduous Forests. Elsevier.

6       Härdtle, Ewald & Hölzel (2004): Wälder des Tieflandes und der Mittelgebirge. Ulmer.

7       Felbermeier, B. & Mosandl, R. (2006): Fagus sylvatica. In Schütt, P. et al.: Enzyklopädie der Laubbäume, pp. 241260. Nikol.


Official site:


Video clip:


Two old Fagus sylvatica (European beech) surrounded by young ones. The tree Jeroen Philippona is standing next to is 40 m tall.
Newly fallen Fagus sylvatica (European beech) in pure F. sylvatica forest.
Fagus sylvatica (European beech), mean diameter 148 cm.
3 tall Fagus sylvatica (European beech). Left to right: unmeasured, 42 metres, 43 m.
The opening in the background, created by several Fagus sylvatica (European beech) falling, now filled with plentiful regeneration. All trees are F. sylvatica.
Carpinus betulus (European hornbeam) group. Background left, bigger Fagus sylvatica (European beech).