Posted: Thu Oct 08, 2015 9:58 am
by KoutaR
Slovakia is known for its numerous prime old-growth forest remnants. The largest of them (tens of square kilometres) are high-elevation Norway spruce (Picea abies) forests. The largest low-elevation old-growth forests, most of them dominated by European beech (Fagus sylvatica), are less than 10 km2, many of them being less than 1 km2 (=100 ha = 247 ac). Larger old-growth beech forests exist especially in Ukraine (88 km2=22,000 ac) and Romania (53 km2=13,000 ac). The preservation of Slovakian old-growth remnants results from their difficult accessibility, the late settlement of the mountainous landscape and the late industrialization of the country. The beginning of the industrial-scale use of the forest and the building of the road net coincided with the creation of the first reserves, i.e. in the late 1800s when there were still thousands of square kilometres of old-growth in Slovakia.

Recently I made a trip with my German friends Thomas and Julia to explore a few Slovakian old-growth reserves. One of them was Dobročský prales = Dobroč Primeval Forest or Dobroč National Nature Reserve in central Slovakia. The reserve is located on a north-facing slope at elevations 720–1000 m. Annual precipitation is 890–960 mm and average annual temperature 4.5–5°C. The reserve was established as early as 1912. The area was originally 50 ha (124 ac) and was later enlarged to 102 ha (252 ac). The original reserve is dominated by European beech and European silver fir (Abies alba), and the newer part by Norway spruce. Two views of the forest:


Thomas' photo. The tree with reddish trunk on the right seems to be Norway spruce. Other trees are European silver firs and European beeches.


European silver firs and European beeches. Two 54-meter firs on the left.

The other trees we saw were sycamore maple (Acer pseudoplatanus), European ash (Fraxinus excelsior) and wych elm (Ulmus glabra). Thomas, who had been in the reserve a few years ago, said there are plenty of big Norway maples (Acer platanoides) at higher elevations where we didn’t visit this time. All these are common trees in European montane forests. The original part is otherwise very close to its natural state, but fir seedlings are missing – a result of roe deer and red deer (European version of elk) over-population in this region. The newer part of the reserve is less natural. The proportion of the fir in the reserve has decreased during the last decades and will further decrease if the herbivore pressure remains high. European silver fir does much better in eastern Slovakia where there are more predators, particularly wolf. For example in Stužica Reserve, which we also visited, there is plentiful fir regeneration, a rare sight in Central Europe today.

The reserve proved to be an optimal site particularly for European silver fir. The tallest firs previously were three 54-meter trees, one in Perućica, Bosnia (viewtopic.php?f=382&t=4747) and two in Biogradska Gora, Montenegro. In Dobroč I measured at least five firs 54 m or more, and the tallest was 56.1 m (184 ft) with the CBH of 407 cm.


56.1-meter European silver fir. Other trees are mostly European beeches and silver firs. In the background probably Norway spruces, too.


Thomas' photo. 56.1-meter European silver fir.

However, the fir was not the tallest tree of the forest. That title went to a 58.1-meter Norway spruce (the record is 62.26 m, viewtopic.php?f=383&t=4642). There were several spruces more than 55 m. Broadleaf trees reach great heights, too. As they were in leaf many were too difficult to measure, so I measured only a few. Nevertheless, I was able to measure a 46.4-meter beech (the record is 49.3 m, viewtopic.php?f=198&t=5400) and a 39.1-meter sycamore maple (the record 41.5 m, ... lle/12183/).


46.4-meter European beech. Other trees are beeches and European silver firs.


39.1-meter sycamore maple, right center. Other trees are European beeches and European silver firs.

The measurements, several decades ago, of Prof. Korpel’ (an important man in the history of European old-growth research) in Dobroč gave the max heights 58 m for fir and 54 m for spruce. This was not the first time that old tangent-measurements have given for fir greater heights than for spruce but laser-measurements suggest that the opposite is true. For my thoughts about European silver fir heights, see message #3 here: viewtopic.php?f=382&t=4747. Prof. Korpel’ also measured a fir with 193 cm (76 in) DBH and 55 m3 (1900 cu ft) volume; that tree fell a few decades ago, the remains are still there.