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> Forest Report 2015 Condition and Use of Swiss Forests FOEN / WSL 2015
4.9 Forest reserves
Peter Brang, Markus Bolliger
> In 2012, 4.8 per cent of the forest area in Switzerland were protected in the form of reserves. This is almost twice as much as in 2005.
> It is also nearly halfway to fulfilling the aim of Swiss forest policy to have reserves on 10 per cent of the forest area by 2030. There is, however, much to do, especially on the Swiss Plateau, and in particular, in the case of large forest reserves.
> In natural forest reserves, the forest is denser and contains more deadwood and giant trees than the rest of the forest.
> In special forest reserves, targeted silvicultural interventions promote particular habitats and species to ensure high biodiversity.
> Some traditional forms of forest use have been continued or reintroduced in special forest reserves: coppice with standards, wooded pastures and chestnut orchards enrich the landscape and provide ideal habitats for light-demanding species.
Types of reserve and target size
There are two types of forest reserve in Switzerland: natural and special forest reserves. In both, the promotion of biodi- versity has priority over other forest functions. Natural forest reserves are left alone, whereas in special forest reserves tar- geted interventions create and improve habitats for particular plants and animals. In 2001, Switzerland set a forest policy target for the size of reserves: By the year 2030, 5 per cent of the forest area should be protected as natural forest reserves and 5 per cent as special forest reserves. In 2012, a total of 4.8 per cent of the forest area was protected: 2.7 per cent as natural forest reserves and 2.1 per cent as special forest reserves. This is almost halfway to meeting the goals for the year 2030 (Fig. 4.9.1; Bolliger et al. 2012), and shows progress in comparison with the Forest Report 2005, when only 2.5 per cent of the area was under protection.
The proportional area of forest reserves is largest in the Jura. On the Swiss Plateau and in the Pre-Alps, the for- est reserves established up to now have been mainly small special forest reserves. In contrast, extensive natural forest reserves have been created in the Alps and on the Southern slopes of the Alps. The greatest need for action for natural forest reserves is thus on the Swiss Plateau.
A further goal of Switzerland’s forest policy is to set up 30 large forest reserves at least 500 hectares in size. Today, there are 17 such reserves, and efforts to provide protection are well underway. Enormous regional differences are, however, evident. It is difficult to create large reserves on the Swiss
Plateau as its forests are productive and easily accessible.
Moreover, they often belong to different owners (section 6.1), who all decide themselves whether to establish a reserve in their forest. The federal government and cantons advise them accordingly and promote forest reserves by providing finan- cial compensation for refraining from using the timber. In addition to the forest reserves, part of the Swiss forest has not
Fig. 4.9.1 Distribution of natural forest and special forest reserves in relation to forest area. Source: FOEN
Proportional area in per cent 4.0
0 1.0 2.0 3.0
0.5 1.5 2.5 3.5
Natural forest reserves Special forest reserves Jura
Swiss Plateau Pre-Alps
Alps Southern slopes
of the Alps Switzerland
> 4 Biodiversity 4.9 Forest reserves 89
been used for decades (section 4.3). It thus includes similar habitats to those in natural forest reserves, even though it is not under protection.
Natural forest reserves
Natural forest reserves should provide habitats also found in virgin forests, which show natural forest development in that the trees grow, regenerate themselves, age and die. During this process, varied habitats for flora and fauna are formed.
The forest reserves include the two remaining virgin for- ests in Switzerland, namely Derborence (Canton Valais) and Scatlè (Canton Grisons) (section 4.3). The other natural forest reserves were used and shaped by people for centuries before they were placed under protection. A monitoring programme in natural forest reserves showed that these forests are grad- ually becoming more natural in that the basal area and the deadwood are increasing, and large trees are becoming more common (Heiri et al. 2012). As a measure of stand density, the basal area is around 30 square metres per hectare in man- aged forests and 40 square metres per hectare in reserves. In natural forest reserves, the forest is thus denser than in man- aged forests. The volume of deadwood (section 4.5) is around 50 cubic metres per hectare and thus higher than the Swiss average of 24 cubic metres per hectare (Herrmann et al. 2012).
Morevover, deadwood in natural forest reserves occurs more often in the form of large trees and in more advanced stages of decay than in the rest of the forest. It is thus biologically more valuable. Giant trees with stem diameters of 80 centi- metres and more are 2 to 3 times more frequent in natural forest reserves than in managed forests (Fig. 4.9.2; section 1.3;
Heiri et al. 2012). In natural forest reserves of beech, light- demanding woody plant species disappear with time as the forest becomes denser, and the species diversity of the trees diminishes slightly. This development is evidence of the increasing near-naturalness of the natural forest reserves. It will probably take centuries, however, before they can be clas- sified as virgin forests (Brang et al. 2011).
Special forest reserves
In special forest reserves, targeted silvicultural interventions promote biodiversity, for example, thinning pine forests so that rare orchids, butterflies and reptiles can live there (Fig. 4.9.3).
Harvesting timber in some conifer forests in the Alps helps to keep them open so that they remain attractive for grouse.
The federal government and cantons provide financial aid for those measures that must be carried out regularly. In special forest reserves, historical cultural forest forms can also be maintained. Many light-demanding species prefer traditional forms of use, such as coppice with standards, wooded pastures or chestnut groves (section 4.7).
Fig. 4.9.3 An open pine forest on a steep slope near Kyburg ZH.
It is regularly thinned so that rare light-demanding forest plants can thrive. Photo: Albert Krebs
Fig. 4.9.2 Over 10 giant trees per hectare grow in the natural forest reserve Leihubel (OW). Photo: Markus Bolliger
