baumzaehlen - Primeval Forests & Their Trees

Annual precipitation is approx. 2000 mm, 15 % of which falls during the three summer months ² . Elevation is 600–2372 m. Average annual temperature is 8–9°C at 700 metres and 5–6°C at 1300 m ² . The lowest area in the northwestern end of the reserve is a steep gorge which is currently almost impossible to enter: the only entry point with slightly gentler slopes would be through Sutjeska Canyon, which is the only part of Perućica suspected of having land mines from the Bosnian War ³ . At higher elevations, gentler and steeper slopes alternate.

The most abundant tree is Abies alba (European silver fir) followed by Fagus sylvatica (European beech) and Picea abies (Norway spruce). Unlike in Central Europe, where roe deer over-population prevents A. alba regeneration ⁴ , herbivores here are controlled by healthy predator populations ³ ; consequently A. alba seedlings are plentiful. The forest is heavily stocked; as much as 1870 m ³ /ha of living wood have been measured in a small research subplot ² . In the steep lower-elevation gorge, more drought resistant broadleaf trees dominate, e.g. Quercus spp. (oaks), Carpinus orientalis (oriental hornbeam), Ostrya carpinifolia (hop hornbeam) and Tilia tomentosa (silver linden).

Many European dendrologists remember Perućica as the place where the tallest P. abies has been measured. The tree in question was 63 metres tall, measured by Prof. Hans Leibundgut in 1954 ² . The measurement is so old that it has certainly been made using the tangent method, which often results in over-measurement ⁵ . However, the forest has plenty of very tall conifers: the measurements by Jeroen Philippona*, Michael Spraggon and myself in 2012 and by Jeroen in 2013 with Nikon 550 laser instruments, gave the maximum height of P. abies as 57.8 metres and that of A. alba as 54 metres. P. abies of about 55 metres are not rare in favourable sites, with A. alba being regularly a few metres lower than P. abies . However, during these trips we had the opportunity to thoroughly explore only a relatively small number of the potential height record groves, so there may well be P. abies exceeding 60 metres. Unfortunately, Prof. Leibundgut did not publish the location of the tallest tree, and the national park administration does not know the tallest trees. Currently, the tallest reliably measured P. abies is 62.26 m and is located in Slovenia ⁶ .

Entrance to Perućica is allowed only with a guide. Camping is not allowed.

* Jeroen’s www-site: bomeninfo.nl/english1.htm

References:

1 Nagel, T. A. & Svoboda, M. (2008): Gap disturbance regime in an old-growth Fagus-Abies forest in the Dinaric Mountains, Bosnia-Herzegovina. Can. J. For. Res. 38 : 2728-37.

2 Leibundgut, H. (1982): Europäische Urwälder der Bergstufe. Haupt.

3 Lalović, V., Sutjeska National Park, pers. comm. (2012)

4 Schütt, P. (1991): Tannenarten Europas und Kleinasiens. Birkhäuser.

5 Bragg, D. C., Frelich, L. E., Leverett, R. T., Blozan, W . & Luthringer, D. J. (2011): The Sine Method: An Alternative Height Measurement Technique. The Forest Service, United States Department of Agriculture, Research Note SRS-22.

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Official site :

http://www.npsutjeska.net/