“Health check” of the Federal government – Its diversity makes the forest stronger as climate change, pests, Ageing – today’s forest report of the Federal government shows the state of the Swiss forests, and points the way for the future.Martin Läubli7 Kommentare7Im means of country wide, more and more deciduous trees. Image: aerial photo of a forest in the Zurich Oberland.Photo: Urs Jaudas

Since the forest debate will not die in the 1980s, is observed in the development of the Swiss forest Plots and by using aerial images and national forest inventory (LFI) documents. Now the fourth reporting is. “The last 35 years have been a success,” says Urs Beat Brändli from the Scientific service NFI at the WSL research Institute in Birmensdorf. The forest is in Switzerland in a good condition, but in certain regions needs to be improved in the future.

Continued growth

the area of The Swiss forest appears to be growing inexorably: in the last eight years by a further 31 000 hectares. This corresponds to a growth of 2.4 percent. Since the first inventory in the 1980s, the forest has increased in area by 11 per cent, or 130 000 hectares. The 1300 square kilometres, as big as the Canton of Aargau.

The development, however, regional differences: In the Central land of the forest has changed hardly any, it grows mainly in the Alps and the southern Alps, above average; 70 per cent of the growth in the last eight years are observed in this Region. The reason for this development is that more and more of the Alps in altitudes above 1400 metres were abandoned.

In the middle of the country is practically no change. The development pressure is huge, but where it is cleared, needs to be replanted elsewhere. The law is written so tightly. The authors of the LFI report, therefore, mainly in the mountain forests of the southern great need for action. The forests Hang in there – managed, often on steep – are “at least maintained”. In addition, the country of immigrant plants, so-called neophytes from wide on the southern side of the Alps, but also in the Mediterranean, will be strengthened. The mountain forest must be in accordance with the LFI report in the future and managed well maintained, its functions mainly as protection forest will continue to be guaranteed. On the southern side of the Alps, only about 16 percent of the forest are, however, developed, in contrast to the Mediterranean country, where 80 per cent are easily accessible.

the protection of the forest is older

a Good 40% of the Swiss forests protect our settlements and infrastructure. You will not keep us from avalanches and rockfall, they prevent both debris flows and slides. The authors of the LFI report, attest to the protection of the forest, although today is a “better protection” than in the last land inventory (2004/06) forestry, because areas have grown with a wide age structure and mixed cultures. Such forests are stable in strong storm events. At the same time, the share of protection forests, in which young trees are planted, but increased. Where the crown of the roof and the trees is dense, is slowed down the taper.

This means that the protection forest is outdated, with the area – especially South of the Alps, where, in many places, the management is difficult. The share of protective forests with insufficient rejuvenation has increased in the last eight years, from 16 to 24 percent. In addition, in some forests the protection forest important know that Anne is suffering under increased deer browsing, which can slow the rejuvenation of solid. “In the long term, the protection effect of forests only through regular management,” write the authors of the report. “The protection of the forest is only accessible to one-third of good care and management is expensive,” says WSL researchers Brändli.

climate politically relevant: supply of Wood

The forest is home to a great climate plays a political role. The ability to store CO2 from the air in the Form of carbon in the biomass, making the tree an important political Instrument. Switzerland should, according to reduce the CO2 law until the end of the year, the greenhouse gas CO2 by 20 percent compared to 1990.

This target will probably be achieved only thanks to the help of the forest, has saved in the last decades, thanks to a growing supply of Wood, more CO2, than he has lost, for example, by storms. In the last eight years, no wind throws, as the storm “Lothar” in 1999. In the same time period the supply of Wood for the whole of Switzerland has increased in the living trees and deadwood by about 4 percent. In the middle of the country, he, however, declined. Also, the forests in Germany and Austria, recorded in the last years an increase of the wood supply. The annual growth of Wood in Swiss forests amounted to 9 million cubic meters, of which almost 90 percent was used, or is available as a deadwood in the forest. The use of wood in Switzerland is about 10 million cubic meters per year.

Under climate pressure

The strong average warming in Switzerland is the forest. The periods with a large forest fire danger have been extended. Brown stained beech forests in the summers of 2018 and 2019, to prepare the professionals to Worry about. Even if the national forest inventory is designed for long-term observation, the WSL has, after the extreme dry periods of different sample surfaces in the short term, are investigated. “We have found no uniform pattern,” says Christoph Hegg, Deputy Director of the WSL. This means that The Book responded differently to the drought.

increases The risk of heat-spread-loving pests in the Swiss forest. The bark beetle from spreading due to the warmer conditions in the last years strongly.

The climate change is reflected in the trees of individual forests. The wood stock of coniferous timber is in the middle of the country on the decline. The wood stock of spruce fell in the middle of the country in the last 35 years by a third. In the virgin forest areas of the deep-dominate pure deciduous forests layers. Stocks, in which a foliage of predominant tree species, have increased in Switzerland easily. The spruce, however, is the whole of Switzerland, the dominant tree species, followed by beech and fir.

But the question of which tree species will thrive in a warmer and drier climate in the future, and wood that yields economically a sufficiently large yield is still open, write the authors in the LFI report. The pine die in the Valais and in the Chur Rhine valley is probably due to increasing dryness. The oak for example, would be less susceptible to drought and is a candidate as a tree of the future. Your stock has grown in the last few years; however, the number of young trees in the Mediterranean country is on the decline, mainly because of deer and deer, the young plants often iron verb.

Also, introduced tree species may be related to climate change is useful: for example, the Douglas fir, the Big coastal fir or the Orient beech. Their share in Switzerland, however, is modest.

in Principle, a positive effect is seen, that the forest in terms of species diversity has increased, which makes the forest to climate change and increased risk of infection by pests more stable. More than 90 percent of today’s forest stands are in total Swiss from pure natural rejuvenation. In the middle of the country, the area with natural tapered stocks, however, is on the decline. This should not, however, be negative, say it in the LFI report. New plantings, the location are fair and are resistant to climate change, could help to ensure a stable forest.

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