Diversity of Slovenia's forests

The forests differ in the predominant species of trees and other vegetation, and they also change with geological base, aspect and altitude, from lowlands and hilly country right up to the upper tree line, which in the Julian Alps is between 1,700 and 1,800 metres above sea level. We present here just some of the main forest groups:

Lowland and low hill forests

In narrow strips, along the rivers and brooks where the earth is periodically flooded, the lowlands are overgrown with willow, alder, ash and oak. By area these forests are small, the only larger ones being the alder forests in Prekmurje and the edges of the Pannonian plain, a peculiarity in those parts where the common alder reaches a greater height and size than anywhere else in Slovenia. These forests (Mala Polana, Črni Log) are also a special feature on the European scale. In the lowlands, here and there can be found some remnants of larger oak forests (common oak), which are protected. One such example is Krakovski Gozd, between Krka, Novo Mesto and Brežice, 150 m above sea level. Krakovski Gozd is protected as a forest reserve. In the hilly areas above the flood plains is the region of oak forests - sessile oak and hornbeam. These are for the most part areas where the forests have now been claimed for farmland.

Extensive beech forests in upland and mountain areas

As we climb from the hills to the mountainous areas, the oak and hornbeam forests change into beech. The beech is the most common species of tree in this country, and covers the major part of the forested area of Slovenia (55%), spreading from the foothills above the oak and hornbeam up to 600 m above sea level and even higher, as Alpine beech forests in the Alps and Dinaric mountains. In the Alpine region it reaches, together with spruce and larch, up to the belt of the dwarf pine-mountain pine (1,600m), while in the Dinaric range pure beech forest reaches up to the dwarf pine belt (Snežnik, 1,500m). The variety of beech forests is further influenced by the geological base and their aspect. The commonness of beech (Slovenian: bukev) is reflected in the names of places such as Bukovje and Bukovica.

Dinaric mountain area and the high Karst plateau

The wide Dinaric region is abundant with communities of beech and fir trees. These are the forests of Kočevje, Notranjska and Trnovska Planota, which in size and density represent a special feature in Europe. Bears and lynx still live in these forests, and even wolves appear occasionally. It is possible to hike through these forests for days without ever emerging onto the plain. The largest extant primeval forests grow in the Kočevje area, the Rajhenavski Rog (51 ha) and Pečka (60 ha) on the Novo Mesto side. In these extant primeval forests we can study the natural development of forests without the influence of man. The main characteristic of these remnants of primeval forests are the old and thick trees which dominate among the fallen or still standing rotting trunks. The growing stock in these forests is over 800 m3 per hectare, and they are difficult to walk in. Many forestry and school excursions from Slovenia and foreign countries come to see these forests, but as they are protected, the foresters only take them along the marked paths by the edges. These forests were protected even by their one-time owner Count Auersperg in the second half of the 19th century.

Spruce from the lowlands to the mountains

The spruce is common throughout Slovenia. In those areas where it would not grow naturally it was disseminated mainly by man for its useful wood. In these areas it is more sensitive to the rigours of the weather and to the more widespread bark beetle. In natural conditions it grows more abundantly only in the Alpine area. The major natural spruce forests in Slovenia are on Pokljuka, Jelovica, Mežaklja and in the Karavanke and Savinja Alps.

The best wood - resonant wood, which forms because of its slow growth - grows on Pokljuka. One peculiarity is the small spruce forests in the Dinaric region, which grow in cold valleys (e.g. Smrekova Draga, and Leskova Dolina in Notranjska) where the temperature conditions will allow only spruce to grow. The temperature inversion in these valleys is such that dwarf pine takes over from spruce as we descend, which is precisely the opposite of the occurrence in the Alps. Spruce forests also cover large portions of Pohorje, where they are for the most part not native. They appeared in the 19th century when the big forest owners clear-cut the original deciduous forests and planted spruce on the clearings. The Sgerm forest estate at Ribnica on Pohorje boasts the tallest living spruce in the European Union, standing at 63 m. Each year it is admired by numerous visitors from Slovenia and abroad.

Pine forests in the Karst and interior of Slovenia

The more extensive pine forests are composed primarily of dwarf pine in the mountain areas, Scots pine and Austrian pine. In nature the Scots pine is a species which grows on the poorest soil where other species of trees cannot take root. It can be found throughout the interior of the country. There are larger dense forests of Scots pine in eastern Slovenia (Goričko) and the Ljubljana basin.

Austrian pine today grows in a large part of western Slovenia, called the Karst, which extends between the Bay of Trieste and the Vipava valley. Historically this part of Slovenia was covered with deciduous forests (oak), but these were destroyed long ago by logging, burning and pasturing. Because of the destruction of the forests the earth began eroding and the cultural landscape deteriorated. Some more progressive foresters began contemplating reforestation. Among them was Josip Ressel, a forester, better known for his invention of a version of the ship's propeller. In 1859 the forester Josip Koller started reforestation of the Karst region. He planted the first successful stand of Austrian pine. Between 1859 and 1914 almost 110,000 ha of the Karst were covered with forests of Austrian pine. This was an extensive and arduous project which involved bringing earth to the planting sites in wicker baskets. In the challenging weather and soil conditions of that area the Austrian pine rewarded their efforts, and today forms a large portion of the Karst forests.

Prepared by Tone Lesnik (2005), Forest Service of Slovenia , Večna Pot 2, Ljubljana