|Originalartikel:||Rigling, A., Schaffer, H.P. (Eds.) 2015: Forest Report 2015. Condition and Use of Swiss Forests. Federal Office for the Environment, Bern, Swiss Federal Institute WSL, Birmensdorf. 144 pages.|
|Autor(en):||Andreas Rigling, Hans Peter Schaffer (Editors)|
|Online-Version:||verändert, Stand: 12.10.2015|
The Forest Report provides information about the condition of the Swiss forests. The data basis is derived from comprehensive monitoring of the forest, which has been established during recent decades, and which enables the condition of the forest to be analysed in more depth. The Report allows insights into the Swiss forest in all its facets, and serves as a reference book for both experts and laypeople.
How is the forest doing? What functions does it perform? And how sustainable is it? The Forest Report 2015, written by scientific and professional experts, explores these issues. It provides information about the forest in all its facets and describes its development since the last Forest Report in 2005.
Answers differ according to the focus of the question, including whether it is about the condition of the protection forest, the development of biodiversity or how successful forestry has been. On the basis of this report, two general conclusions can be drawn.
The present Forest Report 2015 investigates how the condition of the Swiss forest has developed since the publication of the Forest Report 2005. Both forest reports are based on the indicators used in Forest Europe. Their results are therefore directly comparable and can be compared with those of international reporting. The results of the indicator measurements enable an assessment of whether the Swiss forest is being used sustainably. Prerequisites for such an assessment are long-term data series about the condition of the forest ecosystem, based on data from comprehensive forest monitoring conducted since the 1980s. Long-term targets must also be defined, and the federal government has accordingly specified such targets in the Forest Policy 2020.
The forest in Switzerland covers a third of the country’s surface. The forest area in the Alpine regions has increased continuously for 150 years, and by as much as 7 per cent since the 2005 Forest Report alone. In many places stands have become denser. The overall growing stock has increased by a further 3 per cent, although not as much as in the previous period. The growing stock on the Swiss Plateau has, however, decreased, especially that of spruce, which has diminished by almost a third. Since the overall growing stock is greater, the forest serves as a sink for increasing amounts of CO2.
Fig. 1 - Regionally, the forest area has developed differently. It remained the same size on the Swiss Plateau and the Jura between 1985 and 2013, but increased in Alpine regions. Source: NFI
|Fig. 2 - Distribution of carbon stocks in the forest. The forest soil and stemwood together store 75 % of stocks. Source: NFI 2009/2013; Nussbaum et al. 2012|
Since 2005, Swiss forests have been spared disastrous storms. Sulphur deposition from the atmosphere has decreased further. In contrast, high nitrogen deposition and increasing soil acidification still disturb the nutrient balance of trees. Defoliation and tree mortality have remained, on average, stable for many years, but periodically they have increased strongly due to droughts and insect infestations. The rate of unwanted introduction of alien animal, plant and fungal species has continued to increase markedly since 2005. The ongoing climate change will, in future, be even more of a challenge for the forest and forestry.
Fig. 3 - Nitrogen deposition in Swiss forests amounts to between 5 and 65 kg N/ha/year. The threshold values for forest ecosystems are 5–20 kg N/ha/year. Source: FOEN/Meteotest
|Fig. 4 - Bark beetle (Ips typographus): Amount of beetle-infested wood and number of infestation spots in Switzerland from 1991–2012. Source: Waldschutz Schweiz|
Since the Forest Report 2005, both the wood increment and the growing stock have continually increased, while the amount of harvested wood sold has decreased. During the same period, the harvest of logs and industrial timber has decreased and that of energy wood has increased. In addition to wood, non-wood products such as forest honey, venison or mushrooms can also be obtained in the forest. Of the non-wood products, the sudden drop in sweet chestnuts stands out: the harvest has really caved in as a result of damage caused by the sweet chestnut gall wasp. In Switzerland, the use of the forest is covered in the Forest Act. Forest planning implements this legislation and also ensures the sustainability of all forest functions.
|Fig. 5 - Timber use in Switzerland according to the main tree species. Source: Holznutzung NFI 2009/13|
|Fig. 6 - Percentage of the value of the five most important non-wood products harvested in one year. The estimated value of forest honey, venison, mushrooms, Christmas trees and sweet chestnuts in Switzerland amounts in about 87 million Swiss francs. Source: Limacher and Walker 2012|
Forests play a central role in maintaining biodiversity in Switzerland. Since the Forest Report 2005, about half of the forest reserves planned for completion by 2030 have already been established, and the populations of forest birds, large carnivores and wild ungulates have grown. Despite these positive developments, some problem points still remain. Thus open forests and late phases of forest development with old trees and deadwood are rare in the lowlands, and the total number of vulnerable species has not decreased.
|Fig. 7 - Proportional number of stems of different tree species in the Swiss forest. Conifers make up more than half of all tree species. Since 1995, the diversity of tree species has slightly increased and the proportion of broadleaf stands has increased markedly. Source: NFI 2009/13|
|Fig. 8 - Average volume of deadwood in the Swiss forest per economic region. According to the National Forest Inventory NFI, the volume of deadwood doubled in the period from 1995 to 2013 Source: NFI 2009/13|
Forests protect groundwater, an important drinking-water resource, from impurities by retaining pol-lutants in the soil and allowing the cleaned water to percolate deep into the ground. Drinking water from forest areas is therefore of good quality. Forests provide people with protection against natural hazards, like avalanches, rockfall and debris flows. Their protective effect has improved since 2005 because the forests have grown denser. The increasing lack of regeneration and more browsing of young trees by wild ungulates mean, however, that the forest’s long-term protective effect is uncertain.
|Fig. 9 - Main reasons for salvage logging between 1995 and 2006. It corresponds to around a quarter of the total annual use. Such disturbances occur, however, irregularly and with differing magnitudes. Source: NFI 2004/06|
The criterion social economy describes how forestry and the wood industries relate to society. The emphasis here is on the economic and social aspects of sustainable forest management. Since the last Forest Report in 2005, the importance of these aspects and the complex relationships between them have noticeably increased – for example, the way the general public influences forest management. Conflicts over how to use the forest are increasingly the cause and the result. The forest service of wood production and other services such as protection and recreation are increasingly being viewed as related to each other, with wood production re-gaining importance. This development is caused, among other things, by both the energy transition and the generally difficult economic situation of the owners and partners in Swiss forestry.
|Fig. 10 - Federal contributions paid to forestry 1972–2012 in million Swiss francs. Source: FSO and FOEN 2013. Click to enlarge.|