**Postcard depicting an avenue in the Rhone Valley, 1933.** ETH Library Zurich

Rows of trees with many different functions

Our cousins to the north and west boast hundreds of them: tree-lined avenues. Rows of trees are a defining feature of many French and German cities and rural landscapes. Here in Switzerland, avenues have never had the same significance. But they’ve always been here, though. One particular avenue of trees has recently been crowned Switzerland’s “Landscape of the Year 2022”.

Guido Balmer

Guido Balmer is the communications officer for the department of regional planning, environment, mobility and infrastruture of the canton of Fribourg and a freelance communications professional.

Even in antiquity, there were landscapes of trees deliberately planted in neat rows – along the Roman Via Appia, for example. However, it wasn’t until the Renaissance that this type of feature began to be widely used as a means of structuring public space, initially as a “requisite of garden spaces”, and later also as a means of status display in the approach to a castle, and in urban planning. For a long time, these neat avenues were also of great importance for travellers. The trees marked out the route, even on dark nights or in snowy winter landscapes, stabilised the soil, and provided shade.

**Avenue of poplars between Martigny and Brandson, 1926.** ETH Library Zurich

For purposes of military strategy

There has not yet been any comprehensive research into the history of avenues in Switzerland. However, there are a small number of recent publications, such as a 2008 study by the Stiftung Landschaftsschutz Schweiz (Swiss Foundation for Landscape Conservation) and the illustrated book Alleen der Schweiz (Avenues of Switzerland) published in 2017. Historical illustrations and maps show that avenues were also common in Switzerland, especially in the 19th century, and on a local scale they were a defining element of some landscapes and cities – in the Canton of Bern, for example. The first road regulations were published in Bern in 1740, with the aim of improving the network of main roads. Subsequently, all arterial roads in the city of Bern were methodically planted with trees. A decree issued by Bern’s Kriegsrat (council of war) stipulated that the tree species used had to be suitable for military purposes, such as the construction of carts for army use.

Napoleon in particular recognised the importance of avenues for military strategy. He implemented an “avenue plan” that still defines the landscape in many places in France today, but also radiated out into the whole of Europe. In Valais between 1810 and 1820, when Napoleon ordered that the shortest route between Paris and Milan was to be opened up via the Simplon Pass, the relevant roads were set out as was customary in France at the time: lined with poplars on the left and right. Like the avenues of trees in many other places, a significant proportion of these poplars have been felled since the mid-20th century – to allow for more intensive and efficient cultivation of agricultural land, and to expand the road network.

**Thanks in part to Napoleon and his “avenue plan”, much of Europe’s landscape is still characterised by rows of trees.** Wikimedia

For quality of life

Now, however, people have really begun to appreciate the beneficial effects of these avenues. It would be more accurate to say that this consciousness has been reawakened. As early as the dawn of the industrial age, people were aware that these broad, tree-lined avenues were a means of enhancing the quality of life in rapidly growing cities. Avenues were envisaged as places for relaxation, meeting and passing the time of day – one example of this is the avenue of plane trees along the Limmat promenade in the spa district of the city of Baden, an avenue that was created in 1832. People were also aware of the positive influence on bioclimatology at that time. As the process of industrialisation continued to gather pace and traffic volumes increased in the 19th century, this knowledge initially gained in importance, before obstacles gradually got out of hand in the 20th century. Today, this knowledge of the beneficial impact on climate and quality of life is being applied once again, with the planting of trees in streets and public open spaces envisaged as a measure to keep urban environments cooler.

In the wake of this development, there has also been a greater appreciation of existing avenues. In the city of Zurich, there has been an avenue concept in place since 1991, providing for the expansion of existing avenues and the creation of new ones. “Reasons for the planting of these avenues are not only structure and aesthetics; the environmental role of urban trees is also crucial,” according to the city’s official sources. The Alleensicherungsprogramm, the avenue safeguarding programme presented in mid-June 2022 by the authorities in the German state of Mecklenburg-Western Pomerania, is a completely new concept. After Brandenburg, Mecklenburg-Western Pomerania is the federal state with the most avenues, boasting nearly 4,000 kilometres of tree-lined boulevards. Under the new programme, relevant sections of these avenues are to be enlarged and restocked.

**Avenue of blossoming cherry trees in Mecklenburg.** Wikimedia

Preserve, strengthen and continue: these are the goals of avenue projects in the Val-de-Ruz region in the Canton of Neuchâtel, where avenues still cover more than 35 kilometres of the region’s highways and byways. Since 2007, farmers have been working alongside the cantonal department of civil engineering and other authorities to preserve these avenues. New trees are added to avenues with gaps in them. And when roads are renewed, whenever possible, new avenues are laid out. In May 2022, the Stiftung Landschaftsschutz Schweiz awarded the title of "Landscape of the Year 2022" to an expansive landscape featuring an avenue of trees in Val-de-Ruz. In doing so, the Foundation has recognised “the long-standing efforts to restore, regenerate and maintain the avenues and rows of trees that give the Val-de-Ruz landscape its unique character”.

**The maintenance of its avenues has earned the Val-de-Ruz the “Landscape of the Year 2022” award.** Stiftung Landschaftsschutz Schweiz

The story of how this award-winning landscape of avenues came to be is an interesting one. Charles-Alfred Petitpierre-Steiger played a starring role. Petitpierre-Steiger was a state councillor for the Canton of Neuchâtel from 1880 to 1898. In 1873 he had published an article in which he proposed that perry cider be produced in large quantities in order to provide the “labouring classes with a wholesome, abundant and inexpensive beverage”. It was thought this could provide an alternative to the consumption of strong liquor, sales of which always pick up whenever wine is available cheaply. And to ensure there was enough Neuchâtel pear cider, pear trees needed to be planted.

Consequently, in 1887, during Petitpierre-Steiger’s tenure as a state councillor, a cantonal ordinance was issued on the planting of trees along the canton’s roads. In this ordinance, the surveyor is urged to choose fruit trees above other types of tree. The award-winning avenues in the Val-de-Ruz are thus, at least in part, the result of a public health campaign. This clearly shows that there has always been a wide range of reasons for laying out avenues: aesthetic and functional motives, yes, but there were also societal, environmental and health considerations.