Evolution

      Mountains and Alpine habitats

      The Alps are not only Switzerland's most characteristic landscape feature, they are also a symbol of our history and culture. The fate of their diverse habitats and rich biodiversity is inextricably linked to developments in agriculture, tourism and climate. © Felix Wesch

      The Alps are not only Switzerland's most characteristic landscape feature, they are also a symbol of our history and culture. The fate of their diverse habitats and rich biodiversity is inextricably linked to developments in agriculture, tourism and climate.

      Of the 82 peaks that exceed four thousand metres in the Alps, 48 are located in Switzerland or on the Swiss border. This figure alone gives a sense of the tremendous importance of the Alps for our country. The Alps cover more than 60 % of Swiss territory. 23 % of this area lies above 2000 m and accommodates a remarkable biological diversity.

      Where the sub-Alpine and Alpine zones meet, the mountain landscapes in the Alps and on the Jura ridges alternate between dwarf-shrub vegetation and Alpine pastures. In the Alps, this is also where the last larches and stone pines grow. On more open terrain, green alder groves, tall forb meadows and willowherb shape the landscape along with screes and rushing mountain streams. In 2009, Alpine agricultural areas (Alpine meadows and pastures) in Switzerland covered 5139 km2, which corresponds approximately to the area of the Canton of Valais. In the Alpine zone, woody vegetation is replaced by rocky, nutrient-poor grassland and pastures. Glacier forelands and moraines with their pioneer vegetation are also typical features of this environment. Above 2800 m lies the nival level with perpetual snow, boulder fields and screes, where very little vegetation survives. In 2010, glaciers covered an area of 944 km2 in Switzerland.

      Agriculture in transformation

      Mountain farming is in decline throughout Switzerland. The number of mountain farms decreased by 2 % per year between 2000 and 2016. The area of cultivated land remained largely unchanged, however, shrinking by only 0.9 % between 1996 and 2016. The losses are thus much smaller than in the lowlands, where they amount to 3.2 %. However, these figures do not include the summering pastures, which decreased in area by 5.4 % between 1985 and 2009. While the losses apply to the entire Alpine region and a large part of the Jura, it is Valais and Ticino that are most heavily affected. Only in very few regions did pastures expand thanks to clearings, mainly in the Jura, the Napf region and Toggenburg SG.

      Alpine pastures are losing area for several reasons, the most important being the decline of pastoralism. While the numbers of cattle and goats have remained stable in the past few years, the number of sheep held in mountain farms decreased by 26 % between 2000 and 2016. Every year, summering pastures the size of the Walensee (24 km2) are encroached by forest in Switzerland because the cultivation of the often steep slopes is no longer economically viable. The potential natural vegetation on about 60 % of current summering pastures is forest; the pastures exist only as long as they are grazed. The spread of forest, amounting to 3.1 % between 1985 and 2009, occurs to 93 % at the expense of species-rich meadows and pastures.

      Manure is still brought out to many Alpine pastures, leading to a decrease in the supply of arthropods. At these altitudes, the vegetation is generally adapted to low nutrient contents but is exposed to fertilisation by atmospheric nitrogen at a rate of 10 kg/ha. In the long term, this leads to the disappearance of plant species. Among the more recent agricultural practices, the use of stone crushers in low-intensity pastures is particularly disastrous, as the machines break up field and stone formations as well as tree stumps, creating large expanses of level, uniform ground. This practice is already quite widespread in the Jura and has recently been employed in some Alpine regions as well.

      Satellite images clearly show the increase in forest area (dark grey) on the slopes of Monte Bar/Capriasca TI (1816 m) between 1983 (top) and 2015 (bottom).

      © Riprodotto con l’autorizzazione di swisstopo (BA180142)

      The mountains – a popular destination for leisure seekers

      The mountain regions have the lowest population density and the lowest rate of population growth of all Swiss regions. In 2010, the Alpine tourist destinations and the peripheral rural areas that consist of small communities in the Alps, Pre-Alps and Jura far from the urban centres covered 35 % of the territory, but were home to only 4 % of the population. And yet the majority of tourism activities in Switzerland are concentrated in these regions. Although only 1 % of the Swiss Alps have winter-sports infrastructure, it is a dominating feature of the landscape in certain areas. According to estimates, places like Verbier VS or Crans-Montana VS with populations of 3200 and 3400, respectively, in 2016–2017, each accommodate at least 50 000 guests during the peak season.

      In particular, mechanical interventions in the terrain and the use of artificial snow constitute a problem for the Alpine environment. Each alteration of the rocky terrain, especially levelling the ground, increases the warming of the ground and thus accelerates the thawing of permafrost. Snow canons, now employed on 50 % of ski slopes in Switzerland, result in nutrient deposition and cause the decline of specialised and non-competitive plant species. Even several years after the ground has been mechanically levelled, ski slopes harbour fewer species, have patchier vegetation cover and are less productive as farmland than areas that have not had the same treatment.

      The range of leisure activities in the Alps and in the Jura is much more varied today than it was in the 1990s. But trends differ between sectors. Skiing and snowboarding, for example, are declining in popularity: the number of skier days decreased by 25 % between 1993–1996 and 2013–2016. Ski touring, on the other hand, is on the rise. Like other outdoor activities, ski touring generally takes place off-piste. To reduce conflicts between humans and wildlife, a substantial number of refuge zones have been established in the past few years.

      Via ferratas are another type of leisure sport that has recently emerged and that is popular with tourism agencies, because it extends the range of activities available outside of the winter season. In 2015, almost 70 via ferratas were recorded, most of them presumably established after 2000. It is hard to determine exactly how many followers these new types of leisure activities have gained, but the marked increase in members of the Swiss Alpine Club (SAC) is an indirect measure of the trend in mountain sports in Switzerland: SAC membership rose from 87 000 in 1995 to more than 150 000 in 2016.

      Finally, mountain areas also play a role in energy production. 56 % of all reservoirs with a volume of more than ten million m3 are located in the Alps at 1800 m and above. In 2016, 49 % of wind-power plants in Switzerland were concentrated on the ridges of the Jura, the Alps and the Pre-Alps. Several additional wind parks are planned in these areas.

      Change in Alpine agricultural areas between 1979–1985 and 2004–2009, depicted in 1 × 1 km-squares. Mountain farmland is declining in area throughout the Alpine region, most especially in the southern Alps and in Valais.

      © Arealstatistik – Bundesamt für Statistik (BFS) & Amt für Bau und Infrastruktur Liechtenstein.

      The increase in building development in Verbier VS between the 1970s (top) and recent years (2010, bottom) was huge: the residential area almost doubled in size between 1979–1985 and 2004–2009.

      © Mark Shapiro

      The Alps are getting warmer

      Mountain ecosystems are much more heavily affected by the effects of climate change than the lowlands. For example, the average temperature in the Alps has risen by almost 2 °C since the end of the 19th century. That is twice the rate of the average temperature increase in the northern hemisphere.

      The impact of climate warming is most visible in the accelerated retreat of glaciers. Signs of permafrost thawing are evident in unstable slopes and increasing ground movements. Rockfall and debris flows ensue, which in turn increase the risk of damage to infrastructure.

      Climate change has a significant influence on the upward shift of certain specialised high-altitude plants. In the course of the 20th century, botanical diversity increased by 86 % on 37 surveyed summits. At lower altitudes, the same process has become apparent: between 2003 and 2010, butterflies were found to have shifted their range upwards by 38 m. However, this strategy has its limits, as the area of potential habitat shrinks with increasing altitude. Accordingly, declines have already been recorded for several bird species and other groups of animals.

      The fact that less and less precipitation falls as snow is a further consequence of climate change with far-reaching effects. Apart from the negative impact on hydrological balance and glaciers, the reduction in snowfall also affects the economy in mountain regions, as these are still highly dependent on winter tourism. The length of the winter season in ski resorts decreased by more than five weeks between 1970 and 2015, despite the increasing number of ski runs prepared with artificial snow. Today, the season starts an average of 12 days later and ends 26 days earlier.

      Change in the area of glaciers and firn per altitude level between 1985 and 2009. The largest losses occurred between 2600 and 3000 m. But even in the highest zones, the annual accumulation of ice through snowfall can no longer compensate for the melting of glaciers in summer.

      © Bundesamt für Statistik (2015a).

      Change in the area of glaciers and firn between 1979–1985 and 2004–2009, depicted in 1 × 1 km-squares. Glaciers are retreating throughout the Alps, though regions with summits higher than 3400 m are less affected than lower-lying mountain areas like the Gotthard and Adula region or the Engadine GR.

      © Arealstatistik – Bundesamt für Statistik (BFS) & Amt für Bau und Infrastruktur Liechtenstein.

      An ecosystem worth protecting

      Mountain regions have undergone radical change in the past 200 years. Long considered threatening and inhospitable, they inspired the romantic movements in the 19th century and beyond, challenged the first Alpinists, and have more recently attracted crowds of winter-sports enthusiasts. But it is this very appeal of the Alps, heightened by their reputation as the last untouched landscapes in Switzerland, that now presents new challenges. The continuing development of the Alpine region is a balancing act that needs to reconcile transformations in the agricultural sector, a growing variety of tourist activities, and threats to biodiversity, all in the context of global warming. The Alps may appear massive, but the Alpine ecosystems are fragile and require special and well-coordinated monitoring efforts on the part of the eight Alpine countries that take into account both environmental and societal issues.

      Text: Jérémy Savioz

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