Posted: Sat Oct 27, 2012 4:04 pm
by KoutaR

The Sgerm Spruce (Sgermova smreka) in Ribnica na Pohorju, west of Maribor, Slovenia, is named after the farm where it is located.


Vista from the farm. Fruit trees, foreground; Norway spruce dominated forest, background.

The tree is quite well known and cited as one of the tallest (or even the tallest) Norway spruce (Picea abies) in the world. At an altitude of around 500m, the tall spruce is growing near the bottom of a valley in a slight side valley on the NW facing slope.


Grega Sgerm, the owner's son; Blaž Kristan, the owner; and Matic Kristan, the owner's son, at the Sgerm Spruce. Also European silver fir sapling, foreground, and European beech, right.

The forest was originally dominated by European beech (Fagus sylvatica), but Norway spruce and European silver fir (Abies alba) now dominate due to forest management. Beech and sycamore maple (Acer pseudoplatanus) occur, as well as common hazel (Corylus avellana) in the shrub layer. Annual precipitation is over 1000 mm.

The spruce is estimated to be 250 years old. The estimation is based on a ring-count of a neighbouring similar-sized spruce which was felled by wind.

Websites say that the last measurement in 2006 gave its height as 61.8 m. The owners, Blaž Kristan and Damijana Sgerm-Kristan, showed us the report of the measurer, Božo Koler from University of Ljubljana. We saw from the report that the Theodolite measurement had been done very carefully, but it was to the high-slope point, so the tree could be even taller as it is growing on a slope. The owners also gave us earlier height measurements:

1938: 51 m
1980: 57.5 m
1995: 61.7 m; DBH 108 cm

Another spruce on the opposite slope was measured by Koler as 54 m tall.

Laser measurements by Jeroen and Kouta gave 62.2 meters above the average soil level and 61.4 m to the high-slope point. We had been given permission for Michael to climb the spruce and this was the first time that the spruce was to be climbed. Over 10 Slovenians followed the climb: the owner’s family, foresters, the vice mayor of the town, TV cameraman and reporter.


This is Jeroen's photo. The other photos are Kouta's. Part of the "audience". From the left: Matic Kristan, the owner's son; Tomaž Serec, local forester; Miha Mrakič, local forester; the town's vice mayor Aleš Zapečnik; Damijana Sgerm-Kristan, the owner; Grega Sgerm, the owner's son; Rok Držečnik, municipal public utilities clerk; Blaž Kristan, the owner; TV cameraman.

From the summit, Michael measured the highest part of the tree with a folding pole and placed a marker at 4.50 m below the tip. The next part to the point about one meter above the high-slope point was measured by lowering a tape and was 56.23 m. As Michael descended, Jeroen and Kouta defined the average soil level (which was not an easy task!). It was 1.53 m and the high-slope point 0.96 m below the tape measured part of the tree. This gave the total height of the tree as 62.26 meters (204.3 ft.) above the average soil level and 61.69 m (202.4 ft.) to the high-slope point. This is the tallest reliably measured native European tree we are aware of. The original top is still intact.


Michael climbing Sgerm Spruce at about 20 metres. Also young silver firs; sycamore maple foliage, left.

Girth: The CBH is 390 cm (DBH 124 cm) above the average soil level and 361 cm (DBH 115 cm) above the high-slope point.

A 48.4-meter silver fir grows nearby.

Michael's travelogue for this part of our trip can be read here:


Kouta, Michael & Jeroen